1 Finding scholarly information through the Internet and the WWW [email protected] Vrije Universiteit Brussel Information and Library Science,

1

Finding scholarly information through the Internet and the WWW

[email protected]

• Vrije Universiteit Brussel

• Information and Library Science, University of Antwerp

Belgium

Presented atIndian Statistical Institute,

Bangalore Centre, 8th Mile Mysore Road, India28 February 2005

mailto:[email protected]

2

The slides should be available from

http://www.vub.ac.be/BIBLIO/nieuwenhuysen/presentations/

(note: BIBLIO and not biblio)


3

• Databases and computerized information retrieval (on fundamental difficulties in information retrieval, and how to take these into account.)

• Thesaurus systems for better information retrieval.

Continued…

- contents - summary - structure- overview

of this tutorial

4

• Online access information

sources and services (1)» types of information

sources» a systematic overview of

information sources and services that are accessible through the Internet:

» dictionaries and encyclopedias

» Internet subject directories for browsing

» Internet indexes for text searching

Continued…


of this tutorial

5• Online access information

sources and services (2)

»meta-search systems

»the invisible web and how to exploit its contents, even though it is hidden away from text search systems

»finding images/pictures

Continued…


of this tutorial

6• Online access information

sources and services (3)

»finding books

»finding journal articles

»fee-based databases

»using fee-based electronic journals

»open access electronic journals

»using a link resolver to find appropriate documents

End


of this tutorial

7-Interruptions-Questions

-Remarks -Discussions

are welcome

8

Databases and computerized information retrieval

Introduction

9

Comparison

Information retrieval: the basic processes in search systems

Information problem

Representation

Query Indexed documents

Representation

Retrieved, sorted documents

Text documents

Evaluation and

feedback

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Information retrieval systems: many components make up a system

• Any retrieval system is built up of many more or less independent components.

• These components can be modified to increase the quality of the results more or less independently.

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Information retrieval systems: important components

the information content

system to describe formal aspects of information items

system to describe the subjects of information items

concrete descriptions of information items = application of the used information description systems

information storage and retrieval computer program(s)

computer system used for retrieval

type of medium or information carrier used for distribution

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What determines the results of a search in a retrieval system?

• the information retrieval system ( = contents + system)

• the user of the retrieval system and the search strategy applied to the system

Result of a searchResult of a search

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Layered structure of a database

Database

(File)

Records

Fields

Characters

+ in many systems:relations / links

between records

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A simple database architecture: all records together form a database

The ‘salami architecture’ = ‘sliced bread architecture’

»the salami or the bread is a “database”

»each slice of salami or bread is a “database record”

»there are no relations between slices / records

»the retrieval system tries to offer the appropriate slices / records to the user

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Text retrieval and language

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Text retrieval and language: an overview

Text retrieval and language: an overview

Problems related to language / terminology occur1. even when the same language is used in searching and in the searched databases2. in the case of “multi-linguality”: “cross-language information retrieval” that is when more than 1 language is used

»in the search terms

»in the contents of the searched database(s) and/orin the subject descriptors of the searched database(s)

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Text retrieval and language: enhancing retrieval

Text retrieval and language: enhancing retrieval

• Retrieval can be enhanced by coping with the problems caused by the use of natural language.

• Contributions to this enhancement of retrieval can be made by

»the database producer

»the computerized retrieval system

»the searcher/user

• (The distinction between these is not very sharp and clear in all cases.)

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Text retrieval and language: a word is not a concept (a)

Text retrieval and language: a word is not a concept (a)

Problem: A word or phrase or term is not the same as a concept or

subject or topic.

Word

WordConcept

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Text retrieval and language: a word is not a concept (a’)

So, to ‘cover’ a concept in a search, to increase the recall of a search, the user of a retrieval system should consider an expansion of the query; that is: the user should also include other words in the query to ‘cover’ the concept.

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Text retrieval and language: a word is not a concept (a’’)

Text retrieval and language: a word is not a concept (a’’)

»synonyms!(such as : Latin names of species in biology besides the common names, scientific names besides common names of substances in chemistry…)

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Text retrieval and language: a word is not a concept (a’’’)Text retrieval and language: a word is not a concept (a’’’)

»narrower terms, more specific terms (such as particular brand names);including terms with prefixes(for instance: viruses, retroviruses, rotaviruses,...)

»spelling variations (such as UK English versus US English);possible variations after transliteration

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Text retrieval and language: a word is not a concept (b)

Text retrieval and language: a word is not a concept (b)

• Method to solve the problem at the time of database production:

»adding to each database record those codes from a classification system or terms from a thesaurus system that are relevant, and providing the user with knowledge about the system used;in some cases, this process is computerized (with intellectual intervention or completely automatic)

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Text retrieval and language: a word is not a concept (b’)Text retrieval and language: a word is not a concept (b’)

»However, this solution is not perfect:

—Addition of terms by humans from a controlled vocabulary / from a thesaurus is not easy and time consuming. Consequences:

–the added value lags behind the availability of the document

–the process can delay access to the document

–the process is expensive

—Moreover, in practice, most users of the resulting database do not exploit this method offered.

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Text retrieval and language: a word is not a concept (c)

Text retrieval and language: a word is not a concept (c)

• Method to solve the problem, provided by the computerized retrieval system:

»offering to the user a partly computerized access to the particular subject description system used by the database producer, and then linking to the database for searching

»computerized, automatic, analysis of the ‘free text’ search terms applied in a query by the user, for transparent ‘mapping’ to the corresponding particular classification codes, categories, or thesaurus terms used by the database producer

04/18/23

?? Question ??

Which problems in text retrieval are illustrated by the following sentences?

Which problems in text retrieval are illustrated by the following sentences?

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Time flies like an arrow.

Fruit flies like a banana.

?

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28



OK!

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Text retrieval and language: ambiguity of meaning (a)

Text retrieval and language: ambiguity of meaning (a)

• Problem: A word or phrase can have more than 1 meaning.Ambiguity of the meaning of a word is a problem for retrieval. This decreases the precision of many searches.The meaning can depend on the context. The meaning may depend on the region where the term is used.

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Text retrieval and language: ambiguity of meaning (a’)

Text retrieval and language: ambiguity of meaning (a’)

• Example of a word:

»Pascal the philosopher

»Pascal the computer language

Example

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Text retrieval and language: ambiguity of meaning (a’’)

Text retrieval and language: ambiguity of meaning (a’’)

• Example of sentences:

»The banks of New Zealand flooded our mailboxes with free account proposals.

»The banks of New Zealand flooded with heavy rains account for the economic loss.

Example

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Text retrieval and language: ambiguity of meaning (a’’’)

Problem: Ambiguity of meaning

may be the cause of low precision.

WordConcept

Concept

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Text retrieval and language: ambiguity of meaning (b)

Text retrieval and language: ambiguity of meaning (b)

• Method to solve the problem at the time of database production:

»adding to each database record codes from a classification system or terms from a thesaurus system, and providing the user with knowledge about the system used;in some cases, this process is computerized (completely automatic or with intellectual intervention);

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Text retrieval and language: ambiguity of meaning (b’)

Text retrieval and language: ambiguity of meaning (b’)

• Method to solve the problem, provided by the computerized retrieval system:

»offering to the user a partly computerized access to the subject description system and then linking to the database for searching

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Text retrieval and language: ambiguity of meaning (b’’)

Text retrieval and language: ambiguity of meaning (b’’)

»searching normally (without added value), but adding value by categorizing the retrieved items in the presentation phase to assist in the ‘disambiguation’; this feature is offered for instance by

—the public access module of the book catalogue of the library automation system VUBIS at VUB, Belgium, when a searching items that were assigned a particular keyword

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Text retrieval and language: ambiguity of meaning (b’’’)Text retrieval and language: ambiguity of meaning (b’’’)

»Natural language processing of the queries:linguistic analysis to determine possible meanings of the query, which includes disambiguation of words in their context:“lexical” analysis = at the level of the word“semantic” analysis = at the level of the sentenceHowever, most queries are short and therefore it is difficult to apply semantic analysis for disambiguation.

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Text retrieval and language: ambiguity of meaning (b’’’’)Text retrieval and language: ambiguity of meaning (b’’’’)

»Natural language processing of the documents:linguistic analysis to determine possible meanings of a sentence, which includes disambiguation of words in their context:“lexical” analysis = at the level of the word“semantic” analysis = at the level of the sentenceHowever, most retrieval systems do not apply this complicated method.

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A word is not a conceptA concept is not a word

Word1

Word2

Word3

Concept1

Concept2

Concept3

A concept cannot be “covered” by only 1 word or term; this may be the cause of low recall of a search.The meaning of many words is ambiguous; this may be the cause of low precision of a search.

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Text retrieval and language: conclusions

• The use of terms and language to retrieve information from databases/collections/corpora causes many problems.

• These problems are not recognized or underestimated by many users of search/retrieval systems= The power of retrieval systems is overestimated by many users.

• Much research and development is still needed to enhance text retrieval.

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Hints on how to use information sources

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Hints on how to use information sources: overview (Part 1)

• Know the purpose and motivation for each search.

• Do not be lazy: search on your own, before bothering experts with requests for advice.

• Plan your search in advance.

• Choose the best source(s) for each search.

• Use the available tools for subject searching well.

• Try to cope with the language problems;avoid spelling errors in your search query; use spelling variations in your search query

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• Match your search strategy with the type of source.

• Work cost-effectively.

• Use special care when searching for names.

• Be specific. Avoid broad searches.Limit your search to a specific country or region if required.

• Work iteratively.

• Keep a record of your work.

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• Do not only focus on a single source.

• Consider citation indexes besides subject-oriented databases, as useful secondary information sources.

• Stop searching when “enough is enough”

• Give up if necessary... (Not all questions have an answer.)

• Be critical: not all information is correct or useful.

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• In computer-based retrieval systems, consider applying

» truncation of search terms (using a symbol like * or ?)

»combine search terms, using

—Boolean operators: OR AND / + NOT / AND NOT / -

—proximity operators (for instance “NEAR”)

—phrase searching (“word1 word2”)

»searching limited to a field (for instance URL, title…)

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Hints on how to use information sources: subject searching

• When you search for information on a particular topic/subject: investigate if the database producer offers

»a subject classification scheme and/or

»a controlled/approved/accepted subject terms, and/or

»a subject thesaurus

• Exploit these, if they are available.

• In most cases you should find and use synonyms and narrower terms

• Use broader and /or related terms, if appropriate.

46

Hints on how to use information sources: Boolean combinations

Most text search systems understand the basic Boolean operators:

OR = obtain records that contain one or both search terms

AND = obtain records that contain both search terms

NOT= exclude records that contain a search term

47

Hints on how to use information sources: Boolean combinations

In the case of computer-based information sources, use Boolean combinations of search terms when appropriate and when possible.

term x1OR term x2ORterm x3

term x1OR term x2ORterm x3

term y1OR term y2OR term y3

term y1OR term y2OR term y3

term z1OR term z2OR term z3

term z1OR term z2OR term z3

AND AND AND ...

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Hints on how to use information sources: Boolean queries

Most text search systems understand the basic Boolean operators typed in capital characters:

OR

AND

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Hints on how to use information sources: default Boolean operator

• Find out if there is a default implicit Boolean operator working in the search system that you use.

• This works even when no operator is used explicitly among words.

• This can be OR, AND, NEAR...

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Hints on how to use information sources: example of a search query

Example: Searching for the concept “sea” can or should involve for instance the following words in a Boolean OR combination:baltic OR bay OR bays OR coast OR coastal OR coastline OR coasts OR cove OR coves OR gulf OR mangrove OR mangroves OR marine OR mediterranean OR noordzee OR noordzeekust OR noordzeekusten OR ocean OR oceanic OR oceans OR pacific OR reef OR reefs OR “saline-freshwater interface” OR sea OR seas OR seashore OR seawater OR seawaters OR shore OR shores

Example

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Hints on how to use information sources: work iteratively

Work iteratively = search, investigate your results, refine your search, search again, and so on; do not try to find everything in 1 step, with 1 search.

Results

Query Searching

Feedback

52

Hints on how to use information sources: when to stop searching?

Develop a feel for the “curve of diminishing returns”:

If you spend too much time, effort, and/or money with too few benefits, you should stop.

time / effort / money

payoffTime to stop?

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Knowledge organisation: classifications, and thesaurus systems


Introduction

54

• To organise knowledge / documents / books / reports / information / data / records / things / items / materials for more efficient storage and retrieval, some related, similar tools / systems / methods / approaches are used.

• Often but not yet always, this process is assisted by a computer system.

• Good systems are expanded and updated when the need arises.

• The organization system applied should ideally be clearly and immediately visible or even searchable on computer, by the user of the materials.

Knowledge organisation: introduction

Knowledge organisation: introduction

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• Various related tools / systems / methods / approaches are available:

»Classification

»Taxonomy

»Controlled list of selected keywords

»Thesaurus

»Ontology

»Subject-related metadata

»…

Knowledge organisation: some tools

Knowledge organisation: some tools

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Classifications

57

• Universal means here: covering all subjects

• Not just one but several competing systems exist. Examples

»Universal Decimal Classification = UDC

used mainly outside U.S.A.

»Dewey Decimal Classification = DDC

used mainly in U.S.A.

»Library of Congress Classification

used mainly in U.S.A.

» ...

Classification systems: examples of universal systems

Classification systems: examples of universal systems

Examples

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Thesaurus systems

59

Thesaurus: descriptionThesaurus: description

• Thesaurus (contents) =

»system to control a vocabulary (= words and phrases + their relations)

»+ the contents of this vocabulary

• Thesaurus program =

program to create, manage, modify and/or search a thesaurus using a computer

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Thesaurus relations

Thesaurus relations

Term(s) with broader meaning

BT (= Broader Term)

RT (= Related Term) UF (= Use(d) For)Other term(s) Term Synonym(s)

NT (= Narrower Term)

Term(s) with narrower meaning

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Thesaurus applications related to information searching (1)


• For producers of a database: To find/choose index terms to add these to items in a database, when terms are taken from a controlled vocabulary to increase precision and recall in the searches by users of the database.

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• For users (!) of a database:When the database to be searched is produced with added descriptors (words and terms) that are taken from a controlled list of approved, selected words and terms, then the searcher can use some printed or computer-based system first, to find more and ‘correct’ suitable words and terms that belong to that controlled list of descriptors; then, the searcher can use these descriptors (and only these words or terms) in a database query.

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• For users (!) of a database: When the database to be searched is NOT produced with added descriptors (words and terms) that are taken from a controlled list of words and terms, then the searcher can use one or several thesaurus systems first, to find more words and terms and more suitable words and terms; then the searcher can use these found words and terms to formulate a query for that database (to increase recall and precision).

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Thesaurus systems that cover all subjectsThesaurus systems

that cover all subjects

• General systems

• Universal systems

• Covering all subjects

• Broad and shallow systems

• Horizontal systems

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Thesaurus systems that cover all subjects: examples (1)


• Library of Congress Subject Headings (LCSH)

• thesaurus system built into word processing software

• thesaurus system that runs on a pc (independent of Internet) see for instance http://www.wordweb.co.uk/free/

Examples

http://www.wordweb.co.uk/free/

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• thesaurus systems that can be used free of charge through the WWW

»http://education.yahoo.com/reference/thesaurus/index.html

»http://thesaurus.plumbdesign.com/

Examples

http://education.yahoo.com/reference/thesaurus/index.html

http://thesaurus.plumbdesign.com/

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General thesaurus system through the WWW: screenshot sea

Example

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Thesaurus systems covering all subjects: comments

Thesaurus systems covering all subjects: comments

• An ideal, complete thesaurus that covers all subjects does not exist.

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Thesaurus systems focused on a particular subject

Thesaurus systems focused on a particular subject

• Focused on a particular subject domain = narrow and deep, vertical systems

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Thesaurus systems focused on a particular subject: examples

Thesaurus systems focused on a particular subject: examples

• ERIC: education, information science,...

• Psychological Abstracts / PsycInfo

• Sociological Abstracts / SocioFile

• INSPEC: physics, electronics, information technology

• the Aquatic Sciences and Fisheries Information System

• Medline (the Medical Subject Headings = MeSH)

• Various thesaurus systems for art and architecture can be found online: http://www.getty.edu/research/tools/vocabulary/

Examples

http://www.getty.edu/research/tools/vocabulary/



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Classification systems versus

thesaurus systems

72

Knowledge organization:classifications versus thesauri

Knowledge organization:classifications versus thesauri

• Classification

»Good for placement of documents in a library (because documents on many related subjects can be kept together)

»Not well suited for computer searching (too complicated)

• Thesaurus

»Not suited for placement of documents in a library (because documents with related subjects would NOT be kept together)

» Well suited for computer searching (relatively simple alphabetic listing of keywords)

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Online access information sources and services

Introduction

74

Online information sources: summary

• The following gives a general overview of online accessible information sources.

• This overview is not limited to or focusing on a particular concrete subject domain/area.

75

Internet based information sources: problems / difficulties (Part 1)

• Redundancy and overlap:On the one hand, there is too much information on some topics; in other words, the redundancy and overlap are high in many cases. Too few information sources: On the other hand, there are too few information sources on some topics.

76


• No order is imposed on most sources.Quality checks / quality controls are not performed.Related to this: it is not required to register new information offered. Is the information that you find real, honest, authentic?

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• Change is the only constant: Information sources are constantly changing, growing, but sometimes disappearing.

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• Scattering: There is no single simple but powerful system to find relevant information through the Internet.In other words: integration / aggregation is still far from perfect.

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• Slow: The Internet is in many places and for many applications not yet fast enough.

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• In conclusion: Surfing, using the Internet, the WWW, can be a time sink instead of a productive activity.

81

Internet based information sources: how many? how much information?

• More than 10 terabyte (= 10 000 gigabyte) of text data (in 2001)

• More than 10 million WWW sites (in 2003)

• More than 4 000 million (= 4 billion) unique URLs in the total Internet (in 2004)

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Increasing number of online public access databases

Source: Gale Directory of Databases, 1997.Source: Gale Directory of Databases, 1997.

0

1000

2000

3000

4000

5000

6000

7000

1975 1980 1985 1990 1995 2000

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Types of online access information systems

84

Primary versus secondary computer sources / systems / services

• Primary sources /systems /services

directly useful

• Secondary sources /systems /services

»helping to access / use the primary services

»“travel agencies”, “navigation services”, ...

85

Types of online access information systems by contents

• Documents (with or without hyperlinks)

• Catalogues of editors and bookshops

• Online public access library catalogues (OPACs)

• Community/Campus-Wide Information Systems (CWIS)

• Online access databases about journal articles

• Electronic newsletters and journals

• Computer file archives (documents, programs)

• Interest groups (for instance Usenet Newsgroups)

• ...

86

Types of online access information systems by access method

• Remote login information systems and bulletin board systems (BBS) (telnet in the Internet)

• Anonymous ftp servers, in the Internet

• Usenet News servers (nntp in the Internet)

• Gopher servers, in the Internet

• Wide Area Information Servers (WAIS), in the Internet

• World Wide Web servers = http servers (WWW), in the Internet

• ...

87

Types of online access information systems: “free” versus “fee”

Public access information sources free of charge

Fee-based online information services(NOT free of charge)

88

Types of online access information sources by file format

For instance:

»TXT (ASCII)

»DOC

»HTM, HTML, SHTML,…

»PDF

»PCX

»TIF, TIFF

»GIF

»JPG

»PNG

»AVI

»MPG

»ASF

»…

89

Commercial information provided through the Internet

• Most of the information that is freely available on the WWW is provided by commercially oriented organisations.

• Thus that information is not objective or scientific in most cases, but subjective or perhaps even misleading, and certainly attracting more attention than more scientific information.(Of course many information sources are also provided by commercial organisations that belong to the so-called information industry, but these are bound to supply more objective information of high quality, as this is their way to survive commercially.)

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Dictionaries and encyclopaedias accessible through the WWW

91

Dictionaries and encyclopedias through the WWW: introduction

• Dictionaries and encyclopedias are the first choice among many types of information sources,

»when we do not need detailed information on a common topic

»when we want to prepare a more detailed search on an unfamiliar topic, by searching for the right spelling, synonyms, context,…

• Some dictionaries and encyclopedias are available through the WWW free of charge.

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Dictionaries accessible through Internet and the WWW: example

• The American Heritage® Dictionary of the English Language

»Over 200,000 entries, 70,000 audio word pronunciations, 900 full-page color illustrations

»Available free of charge from http://education.yahoo.com/reference/dictionary/

Example

http://education.yahoo.com/reference/dictionary/



93

Dictionaries accessible through Internet and the WWW: compilation

• A compilation/collection of dictionaries can be searched simultaneously and free of charge: http://www.onelook.com/

Example

http://www.onelook.com/

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Encyclopedias accessible through Internet and the WWW: examples

• Encarta Concise Free Encyclopedia

»http://encarta.msn.com/

»Available in English and in some other languages

Example

http://encarta.msn.com/

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• Encyclopædia Britannica only a small part is available free of charge + links to selected WWW sites

»http://www.britannica.com/

• Encyclopædia Britannica Concise

»http://education.yahoo.com/reference/encyclopedia/

Example

http://www.britannica.com/

http://education.yahoo.com/reference/encyclopedia/

96


• The Canadian Encyclopedia(in English and in French):

»http://thecanadianencyclopedia.com/

Example

http://thecanadianencyclopedia.com/

97

Encyclopedias accessible through Internet and the WWW: overviews

• A list / overview of encyclopedia on the Internet:http://www.internetoracle.com/encyclop.htm

• Other lists of encyclopedia on Internet can be found as a part of more general directories of Internet-based information sources.

Example

http://www.internetoracle.com/encyclop.htm

http://www.internetoracle.com/encyclop.htm

98


Internet search functions built in browser software

99

The Internet search functions built into browsers

• Some Internet search functions are built into common leading browsers like

»Microsoft Internet Explorer

»Netscape

• When connected to the Internet, you can use

»The functions behind the “Search button”

»Searching through the “Address” form

100

The Internet search button of browsers: introduction

Common graphical browsers provide a search function and a search button. Examples:

Netscape, Microsoft Internet Explorer

101

The Internet search button of browsers: comments (Part 1)

• Such a search function offers in fact no searching, but (only) a link to a WWW site, often in the USA, which offers links or gateways to search tools on other servers.

• It is faster in many cases to contact search tools directly.

102

The Internet search button of browsers: comments (Part 2)

• The gateways may offer only a limited view on the properties of the real search tool used.

• Such a search function can confuse users who may think that the searching capability is built more or less into the browser software, while searching relies on external servers.

103

Searching with browsers using the address form: introduction

• A search for particular Internet documents can be performed by typing in keywords in the address form, when you are connected to the Internet,for instance with

»Microsoft Internet Explorer

»Netscape

• This is based on transmitting the keywords to some Internet index through the Internet.

104

Searching with browsers using the address form: comments

+ An advantage is the ease of use.

- A disadvantage is that it is less clear what really happens, than when you access a well chosen and well known Internet directory or Internet index directly.

105


Internet directories and indexes

106

Internet: meta-information about Internet information sources

• in printed manuals and guides:

- it is not always possible to get a copy fast

- it costs money to get a copy

- they are soon out of date

• offered on the WWW!:

+ directly available when we want to use the Internet

+ many systems are accessible free of charge

+ most systems are regularly updated

• (“intelligent agent” software on client PC)

107

Internet: subject-oriented meta-information offered via WWW

Information about information sources: in the form of

»subject guides = texts with references

»subject hypertext directories = subject guides

»key word indexes, generated automatically, for searching

»collections of links or forms to the above

»(multi-threaded search systems)

108

Internet global subject directories:introduction

• They are virtual libraries with open shelves, for browsing.

• They are manually generated, man-made by many people.

• They can be browsed following a tree structure or a more complicated variation.

• The most famous of these systems belong to the most popular and most visited sites on the WWW: e.g. Yahoo!

109

Internet global subject directories: structure

The structure corresponds to a classification that is in most cases specific for the particular overview. In other words: the well-known and classical universal classification systems are not used in most Internet directories.

110

Internet global subject directories: pros and cons

• They cover a small number of selected WWW sites, in comparison with the total number of sites that are accessible.

+ The selected, included sites should be better than average.

- They are not suitable for deep, detailed, specific searches with a high coverage.

111

Internet global subject directories:why use one?

• They are suitable mainly for broad searches that can be difficult to formulate in words, but NOT for more specific searches that require combinations of several concepts.

112

Internet global subject directories:searching directories with a query

• Many of the Internet directories include an index to search their contents with a query.

• However, then the assisting classification structure is not well exploited and the user should be aware of the problems and difficulties of information retrieval with natural language queries.

• Furthermore, the possibility to use the system in this way may be confusing, as these directories are not real full-text Internet indexes, like those provided by other search tools.

113

Internet global subject directories: Yahoo!

• A hypertext global subject directory can be found at http://www.yahoo.com/

and at many other sites, includinghttp://www.yahoo.co.uk/

• Entries are NOT rated.

• Accessible free of charge.

Example

http://www.yahoo.com/

http://www.yahoo.co.uk/

114

Internet global subject directories: Yahoo! links in pediatrics

• Health > Medicine > Pediatrics:• International Pediatric Chat - for professionals to share information and education

regarding children's health care.

• National Med/Peds Residents' Association - organization for residents, practioners and medical students interested in combined internal medicine and pediatrics.

• Neonatology Network - information and communication platform for neonatologists and pediatricians.

• Pediatria OnLine - qui si parla di bambini, fra pediatri e con le famiglie.

• Pediatric Critical Care

• Pediatric Database (PEDBASE) - containing descriptions of over 500 childhood illnesses.

• Pediatric Endocrinology Conference - LWPES/ESPE joint meeting occuring July 6-10 2001.

• Pediatric Endoscopic Photos - illustrating intestinal problems in children.

Example

http://srd.yahoo.com/drst/28916965/*http://www.pedschat.org/

http://srd.yahoo.com/drst/6573636/*http://www.MedPeds.org/



http://srd.yahoo.com/drst/957354/*http://www.neonatology-net.com/

http://srd.yahoo.com/drst/734470/*http://www.pediatria.it/



http://srd.yahoo.com/drst/142288/*http://PedsCCM.wustl.edu/

http://srd.yahoo.com/drst/405482/*http://www.icondata.com/health/pedbase/index.htm

http://srd.yahoo.com/drst/38294975/*http://www.med.mcgill.ca/pedendo

http://srd.yahoo.com/drst/8304521/*http://www.vh.org/Providers/TeachingFiles/Endoscopic/Endoscopic.html



115

Internet global subject directories: Yahoo! for pediatrics

• Health > Medicine > Pediatrics:link to a digital library (health sciences) for young patients

Example

116

Internet global subject directories: Yahoo! to pediatrics organisations

• Health > Medicine > Pediatrics > Organizations:link to the American Academy of Pediatrics

Example

117

Internet global subject directories: Yahoo! links to pediatrics schools

• Health > Medicine > Pediatrics >Schools, Departments, and Programs

• University of Rochester - partnership between pediatric residents and community-based agencies that serve children and their families.

• Michigan State University@

• Royal College of Paediatrics and Child Health - responsible for training, examinations, professional standards, and organisation of child health services for the UK.

• Tohoku University

• University of Alabama at Biringham - programs and training opportunities in pediatrics. Also contains faculy information and sub-speciatlty descriptions.

• …

Example

http://srd.yahoo.com/drst/42668399/*http://www.plccare.org/

http://dir.yahoo.com/Regional/U_S__States/Michigan/Cities/East_Lansing/Education/College_and_University/Public/Michigan_State_University/Departments_and_Programs/College_of_Human_Medicine/

http://srd.yahoo.com/drst/27832083/*http://www.rcpch.ac.uk/



http://srd.yahoo.com/drst/9149711/*http://www.ped.med.tohoku.ac.jp/

http://srd.yahoo.com/drst/13146630/*http://www.peds.uab.edu

http://srd.yahoo.com/drst/13146630/*http://www.peds.uab.edu

118

Internet global subject directories: searching with a query in Yahoo! (1)

• The directory of Yahoo! can not only be browsed, but can also be searched with a query.

• However, in this way the hierarchical structure is not well exploited.

• For the formulation of a search query, Yahoo! can provide automatic assistance related to spelling and word variations. For instance: After searching for “Capetown”, Yahoo! Answers: Other Spellings: Try searching for cape town instead.

Example

http://srd.yahoo.com/sp/top/capetown/cape+town/?http://search.yahoo.com/search?p=cape+town&sp=1

119

Internet global subject directories: searching with a query in Yahoo! (2)

• When such a query does not provide results, then Yahoo! uses a much larger external Internet index, to execute a query based on textual search statements.

• The chosen Internet index has varied over time.

• This mechanism is not made very clear and may confuse the user.

Example

120

Internet global subject directories: Yahoo! and full-text search engines

• The company Yahoo! started and became famous by offering a WWW global subject directory.

• Afterwards it has offered many other services and has become one of the mostly used WWW portals.

• In 2003, Yahoo! also owns 3(!) big Internet search engines: All the Web, AltaVista, Inktomi

Example

121

Internet global subject directories: Britannica

• A hypertext global subject directory can be found athttp://britannica.com/

• Entries are rated.


• Combined and integrated with a great encyclopedia.

Example

http://britannica.com/

122

Internet global subject directories: BUBL link

• A hypertext global subject directory to more than 10 000 WWW sites for the higher education community can be found athttp://bubl.ac.uk/link/


Example

http://bubl.ac.uk/link/

123

Internet global subject directories: Google directory

• A hypertext global subject directory can be found athttp://directory.google.com/


• Based on the Netscape DMOZ Open Directory Project.

• Do not confuse this with the famous Google WWW search engine.

Example

http://directory.google.com/



124

Internet global subject directories: Librarians' Index to the Internet

• A hypertext global subject directory can be found athttp://www.lii.org/


Example

http://www.lii.org/

125

Internet global subject directories: Open Directory Project

• A hypertext global subject directory can be found athttp://www.dmoz.org/

• The contents is also used in other systems,such as Google Directory and Webbrain.


Example

http://www.dmoz.org/

126

Internet global subject directories: Resource Discovery Network

• A collection of hypertext subject directories that focus on academic information sources can be found athttp://www.rdn.ac.uk/

• Together these lead to more than 30 000 selected WWW sites.


Example

http://www.rdn.ac.uk/

http://www.rdn.ac.uk/

127

Internet global subject directories: evaluation criteria - desiderata (1)

• Usage free of charge?

• Wide coverage?

• Up to date? Frequent updates? Only few dead / broken links?

• Good coverage of the sources in that part of the world in which you are interested?

128


• Does the manager of the directory refuse to give priority to sites that want to pay to get a prominent place in the directory?

• Easy user interface?

• Short response times?

• Are mirror sites available closer to you for faster response?

• Good presentation, description of each site?

129


• Is a rating, appreciation, review offered for each listed site?

• Is translation of documents offered free of charge?

• Good documentation and online help?

• Good help desk available?

• High stability and reliability?

130


• Are other services offered from the same site or with the same interface? Is the subject directory integrated with other services?Additional services can be

»an Internet index or a WWW index or a gateway to such an index for searching with a query

»weather, travel guides, flight and hotel reservations, maps,...

»WWW-based e-mail and e-mail address directories

»auctions through WWW

131

Internet subject directories: non-global, more specific systems

a directory limited to sources in/of a country or region

a directory restricted to a specific subject domain

(“portal”)

a global subject

directory

the complete WWW

can lead to

132

Internet subject directories focusing on a specific subject domain (Part 1)

“Specialised subject directories” or “gateways”

Examples:

• Educational materials in the USA:

»http://www.thegateway.org/

• Marine science and oceanography:

»http://oceanportal.org/ = http://ioc.unesco.org/oceanportal/

Examples

http://www.thegateway.org/

http://oceanportal.org/

http://ioc.unesco.org/oceanportal/



133

Internet subject directories focusing on a specific subject domain (Part 2)

• Engineering, mathematics, computing:

»http://www.eevl.ac.uk/

»http://www.ub.lu.se/eel/

• Civil engineering:

»http://www.icivilengineer.com/

• Fishing:

»http://www.onefish.org/

Examples

http://www.eevl.ac.uk/

http://www.ub.lu.se/eel/



http://www.icivilengineer.com/



http://www.onefish.org/

134

Internet indexes:automated search tools

• Several systems allow to search for and to locate many items (addressable resources) in the Internet in a more systematic, direct way than by only browsing/navigating.

• These systems do NOT search the contents of computers through the real Internet in real time and completely when a user makes a query. Searching in that way would be much too slow due to limitations in the technology.

135

Internet indexes: scheme of the mechanism

User searching for Internet based information

Internet client hardware and software

user interface to a search engine Internet information source

Internet index search engine Internet crawler and indexing system

database of Internet files, including an index

136

Internet indexes:description of the mechanism

Each of these search systems is based on:

• a database of links to pages / URLs that can be retrieved by searching with queries through a big index that is built machine-made on the basis of the contents, the texts, of these pages(to build this database and to keep it up to date, pages are continuously collected from the Internet by a “robot” computer software system)

• a search system with a user interface in a WWW form, to allow the user to search through that database

137

Internet indexes: building their database

Inverted file, full text index,

register of the database

UserUser

Records derived from the input

and stored in the database

Internet documents fed into the database management system

Indexing

Retrieval

138

Internet indexes:AltaVista

• The primary search interface can be found in the US. The following addresses all lead to the same information:

»http://www.altavista.com/

»http://www.av.com/

»http://av.com/

• Mirror site in UK:

»http://uk.altavista.com/

»http://www.altavista.co.uk/

http://www.altavista.com/



http://www.av.com/

http://www.av.com/

http://www.av.com/

http://av.com/

http://av.com/

http://av.com/

http://uk.altavista.com/



http://www.altavista.co.uk/



139

Internet indexes:AltaVista: features

• Allows full text searching of the WWW

• Offers relevance ranking of search results

• Allows also advanced Boolean searching (in “Advanced” mode)

• Offers a link to an Internet subject directory (Looksmart)

• Offers links to systems to find images, sounds… (multimedia) in the Internet

140

Internet indexes:AltaVista as a company

• AltaVista and the other leading Internet search engines Alltheweb and Inktomi are owned by the same U.S. company Yahoo! since 2003.

• Their most important competitor is Google.

141

Internet indexes:All the Web

• The search interface can be found at:http://www.alltheweb.com/http://alltheweb.com/

• You can search the WWW and ftp servers.

• The database is one of the biggest.

• Not only HTML and plain text files, but also the full text of many Adobe PDF files is indexed.

• Offers also a module to search for pictures/images.

• Offers spelling suggestions in the search interface.

http://www.alltheweb.com/



http://alltheweb.com/

142

Internet indexes:All the Web as a company

• All the Web and the other leading Internet search engines AltaVista and Inktomi are owned by the same U.S. company, Yahoo!, since 2003.

• Their most important competitor is Google.

143

Internet indexes: Google (Part 1)

• http://www.google.com/

• One of the most popular systems in 2001, 2002, 2003, 2004…

• For retrieval, an algorithm is used that takes into account the links between WWW pages.A retrieved page is ranked higher when

»many sites/pages point to it

»“important” sites/pages point to it

http://www.google.com/

144


• Full-text searching is possible of many files that are available through the WWW.

• Not only HTML and plain text pages are covered, but also the first part is indexed of many files in other file formats, such as

»Adobe PDF,

»Microsoft Word, Microsoft Excel, Microsoft PowerPoint

»Rich Text Format…

145


• Also the contents of some databases can be searched. In other words, not only static WWW pages are harvested and made searchable.

• Many other search systems on all kinds of WWW sites are based on Google.

146

Internet indexes: Google refers to a dictionary

• In Google, the words used in a search query are returned to the user with hyperlinks to a dictionary and to a thesaurus on the WWW, that can be used partly free of charge.

• The dictionary can learn the user more about the meaning of the words used in the query.

147

Internet indexes: Google refers to a dictionary: display

Example

148

Internet indexes: from Google into a dictionary

Example

149

Internet indexes: Google refers to a thesaurus

• In Google, the words used in a search query are returned to the user with hyperlinks to a dictionary and to a thesaurus on the WWW, that can be used partly free of charge.

• The thesaurus can of course show the user synonyms, narrower terms, related terms for the word.In this way, this system can be used to expand a search query, so that the query better covers the search concept.

150

Internet indexes: from Google into a thesaurus

Example

151

Internet indexes: Google can expand a query: how?

• If you want to retrieve more documents, then you can request Google to include synonyms of one or several of the words in your query in an automatic way.

• This works since 2003.

• You can do this by putting a tilde ~ in front the selected word.

• Example of a query: word1 ~word2 word3 word4

152

Internet indexes: Google can expand a query: comment

• Of course, this is only a “quick and dirty” method.The system does not really understand your information need. Manual, intellectual expansion of a query should yield better results.

153

Internet indexes: Google Scholar

• Google Scholar allows us to search for more scholarly information sources, including journal articles.

• A beta (test) version was available since November 2004.

• The system is accessible starting from the home page of Google as one of the additional services.

• The online manual explains the system:http://scholar.google.com/scholar/about.html

• The information is harvested in a more or less automatic way from the public WWW and from databases of some scholarly publishers.

http://scholar.google.com/scholar/about.html

154

Internet indexes: Google additional features

• Besides a system to search for WWW pages, Google offers also »a subject directory» its own big database to search for images/pictures

»searching an archive of Usenet messages + posting to Usenet groups

»searching for news

»Google Scholar to search for more scholarly information sources

»Google Print to search in the contents of books

155

Internet indexes: Google as aggregator

• Google has become a great integrator / aggregator of systems to access information.

156

Internet indexes:Google as a company

• The important competitors of Google are

»The well-established, classical Yahoo! subject directory system

»The Yahoo! search engine, new since 2004

»All the Web and AltaVista well-established Internet search engines

• These are all owned by the same U.S. company, Yahoo!, since 2004.

157

Internet indexes: MSN Web Search

• Offered free of charge by Microsoft.

• You can search for WWW content.

• Since 1998.

• Famous system, because the search interface can be found with the search functions that have been built into one of the most widespread Internet browser, Microsoft Internet Explorer, and because it is offered by http://search.msn.com/

Example

http://search.msn.com/



158

Internet indexes: MSN Web Search

• Is based on an Internet index created by another company, up to 2005.But in 2003, Microsoft has started building its own WWW crawler and search engine.

Example

159

Internet indexes: Scirus

• Allows you to search for manually selected scientific information (only) on the WWW. This includes

» the peer-reviewed articles in the journals that are published in ScienceDirect by Elsevier, that can be downloaded in full-text format, only when a fee has been paid to the publisher

»scientific open archives files, that contain scientific research articles that can be downloaded free of charge.

• The search interface: http://www.scirus.com

Example

http://www.scirus.com/


160

Internet indexes: Scirus features

• Offered free of charge by Elsevier.

• Is partly based on the Fast WWW search system that is also used by Alltheweb.

• Offers access to information ordered according to some classification system / taxonomy.

• Offers not only access to files in html format, but also to files in PDF.

Example

161

Internet indexes: Scirus: screenshot

Example

162

Internet indexes: Teoma

• Allows you to search for information on the WWW.

• Offers a feature that is not offered by most other search systems: categorization = classification = refinement = categorization = clustering of search results, to help the user coping with the problem of ambiguity of meaning of the search query that was made

• The search interface: http://www.teoma.com/

Example

http://www.teoma.com/



163

Internet indexes: Teoma example

Example of coping with ambiguity: searching for pascal gives results related to the philosopher and to the computer programming language:

Example

164

Internet indexes: Mooter


• Offers a feature that is not offered by most other search systems: categorization = classification = refinement = categorization = clustering of search results, to help the user coping with the problem of ambiguity of meaning of the search query that was made.The clusters are displayed in a diagram.

• The search interface: http://mooter.com/

Example

http://mooter.com/

165

Internet indexes: WiseNut


• Offers a feature that is not offered by most other search systems: categorization = classification = refinement = categorization = clustering of search results, to help the user coping with the problem of ambiguity of meaning of the search query that was made.

• The search interface: http://www.wisenut.com/

Example

http://www.wisenut.com/

166

Internet indexes: WiseNut: screenshot of the guide

Example

167

Internet indexes: Yahoo!

Example

• An Internet search system is offered through http://www.yahoo.com/

• This is offered besides the well-established, classical Yahoo! subject directory.

• Before 2004, the search system was provided by an external company, most recently by Google.Since 2004, an independent system is offered that is competing with other similar systems.It is probably based on the well-established INKTOMI Internet database that is owned by Yahoo! since 2003.

http://www.yahoo.com/

168

Internet indexes: coverage

• Internet indexes do not cover all static documents on the WWW.

• Most indexes grow and their “size ranking” is variable.

• If exhaustive results are desired, then more than one Internet index search system should be used.

169

Internet indexes: coverage and size of each index

• Most indexes grow and their “size ranking” is variable.

• The biggest systems in 2004-2005:

» Google !

» Yahoo search

» AltaVista

» All the Web

» Systems based on the INKTOMI database of WWW pages.

170

Internet indexes: delay in indexing new pages

• The great, well known, international Internet indexes have a delay of more than 1 month in indexing new pages. (according to Lawrence and Lee Giles, Nature, 1999, Vol. 400, pp. 107-109.)

• So they are not suitable to search for rapidly changing recent information (such as “news”)(unless they index a small selection of important news sites more frequently.)

171

Internet indexes: specialised systems

• More specialised search engines / systems can yield better result sets:

»higher recall

»higher precision

• Specialised Internet indexes / search engines can be found for instance in the directory

http: //directory.google.com /Top /Computers /Internet /Searching /Search_Engines /Specialized/

http://directory.google.com/Top/Computers/Internet/Searching/Search_Engines/Specialized/





172

the complete WWW

covered by a global / international Internet index

covered by an index limited to

sources in/of a country or region

Internet indexes: non-global, regional systems

173

the complete WWW

Internet indexes: subject-specific, specialised systems

covered by a global / international Internet index

covered by an Internet index limited to

sources related to a specific subject

174

Internet indexes: comparison with library catalogues

• Most Internet indexes have a larger database than most catalogues.

• Internet index databases do not correspond as well to the Internet as a normal, good catalogue corresponds to the collection, because the documents on the Internet change more often and their number is growing fast.

• Most Internet indexes contain all the words of the documents that they index, whereas catalogues only contain short descriptions of the documents.

175

Internet indexes: variations among various systems

• Besides their common aims and characteristics, we can nevertheless see differences, variations among the searchable Internet index systems.

• To illustrate these variations and to assist Internet users to make a decision on which search system to use, the following list of some features and evaluation criteria can be useful.

176

Internet indexes: general evaluation criteria - desiderata

• Is usage free of charge?

• How complete is the coverage?

• Is the coverage good (or poor) for a particular geographic region?

• Is the coverage good (or poor) for a particular type of documents?

• Is the searchable database up to date? Is the database updated frequently? Do the search results contain only few dead (broken) links?

177

Internet indexes: indexing + searching

evaluation criteria - desiderata (1)

• Does the database system work with full text indexing of each document that has a place in the database, so that full text searching is possible?Is the complete text indexed and searchable, even for very long documents?

178

Internet indexes: indexing + searching evaluation criteria - desiderata (2)

• Are the contents of meta-fields also indexed to make them searchable?

179



• Does the system index also the text in files on the web that consist of non-ASCII codes to make these also searchable and retrievable? For instance files in the format of the various versions of

»Microsoft Word (DOC), Microsoft PowerPoint (PPT, PPS), Microsoft Excel

»Adobe Acrobat Portable Document Format (PDF)

180



• Field indexing, so that searching limited to the contents of a particular field is possible? for instance:

HTML title, HTML keywords,

URL, date,

link, Java applet,

text, image file,

sound file, video file...

181


• Does the system offer powerful search options like

»searching for terms composed of several words, in queries like “word1 word2” with the words enclosed in double quote characters

»truncation of words in a query?

»Boolean search combinations?

»an unlimited number of search terms in a query?

»proximity/nearby/adjacency searching, with operators like “word1 NEAR word2” or “word1 ADJ word2”

182


»spelling check of search terms in the query, and suggesting spelling variations?

»automatic expansion of the search terms in the initial user’s query, to achieve a higher recall, for instance by

—automatic stemming of words in a query

—including synonyms

—including narrower terms

—including translations into several other languages

183


• Can the results be limited to a certain time period? For instance based on the date

»of the file as noted by the server computer, or

»of the most recent indexing of the file

• Is the user interface easy to understand and efficient to use?

• Is a user interface offered in your own language?

184


• Is the search/query also submitted to another database to obtain more results? for instance: to a book database to obtain book descriptions besides WWW documents

185


• Is spamming filtered out, to give other pages a better chance of turning up in the result set?Can the system cluster presumed duplicate documents in the results? Or does the system simply eliminate presumed duplicate documents from its database?

186

Internet indexes: output evaluation criteria - desiderata (1)


• Are mirror sites available closer to you for faster response?

• Does the system rank the items in the result set according to their presumed relevance?

• Possibility to combine Boolean retrieval with relevance ranking of results?

187


• Can the results be ordered according to date

»of the file as noted by the server computer, or

»of the most recent indexing of the file

• Can the results be ordered according to size?

• Can the system rank the results (documents) on the basis of the number of WWW hyperlinks to that document?

• The system does NOT place/rank some results (documents) higher in the results list, on the basis of payments by the producer of those documents to the search system company.

188


• Are advertisements / sponsored links / sponsored results clearly distinguished from normal (not sponsored) search results?

• Good and detailed summary of each result available?

• Does the system offer a good presentation format of each result (document/page/item)?For instance: are search terms indicated / highlighted in the results?

189


• Is any evaluation offered (automatic?) of the quality of each result, besides ranking in an order related to probable relevance and importance of the results?

• Can all the results (documents) from the same site be grouped together (clustered)?

190


• Are results (retrieved documents) grouped / classified / categorized / clustered by the search system, on the basis of the subjects of the documents and are these presented as groups / clusters / classes / categories to the user of the search system, to assist the user in coping with the problems that can be caused for instance by multiple meanings of words used in a search query.

191


• Is translation offered free of charge of the search result set, that is the list of brief descriptions of retrieved documents?

• Is any fact extraction from the information sources offered, in an attempt to answer the query more directly than by offering only links to documents?

192


• Term suggestion: Does the system analyse the search results of the first query, to find frequently occurring terms and to suggest these to the user as new and potentially interesting additional query terms?

• High stability and reliability?

• No large variations/fluctuations in the results from identical searches at different times.

193


• Relevance feedback:Can the user indicate among the search results of a first query the “good, relevant” and the “bad, irrelevant” results, so that the system can use this information to offer better results in a second query?

194


• Relevance feedback 2: even better: Can the user indicate among the search results of a first query + “good, relevant” results, - as well as the “bad, irrelevant” results, so that the system can use this information to suggest + additional, new interesting query terms that can be included in a second query, - as well as query terms that should be excluded in a second query?

195


• Does the system check automatically and directly the availability/reachability of WWW pages that correspond to the hyperlinks that the system has retrieved based on your search?The system can then discard invalid/broken links from the results set.This is useful because some links may be “dead/broken” even when they were included earlier in the search system.The Internet and the WWW are volatile media.

196

Internet indexes: help evaluation criteria - desiderata

• Is good documentation and online help available free of charge?

• Is a good help desk available?

• Does the system clearly explain which contents (information) is harvested and made searchable and which not, and how completely this contents is covered?

• Does the system clearly explain the mechanism that is applied to rank the search results in the output?

197

Internet indexes: current awareness evaluation criteria - desiderata

• Can the search system provide updated results, based on your interest profile, through electronic mail for instance, as a current awareness tool?

198

Internet indexes: other services evaluation criteria - desiderata

• Other services available besides the normal WWW index:

» index to news resources, that is more frequently updated?!

»Internet subject directory?!

»anonymous ftp file index?

»gopher index?

»searchable Usenet newsgroups archive?

»white pages = people finder = addresses = ...



199

?? Question ??

Why do different Internet search engines (in most cases)

give different results for an identical search, even though they have access

to the same (all) documents on the Internet?

Why do different Internet search engines (in most cases)

give different results for an identical search, even though they have access

to the same (all) documents on the Internet?

200

?? Question ??

In spite of the high popularity and the quality of the Google Internet index search system,

there are still limitations in the search features.

Which limitations?

In spite of the high popularity and the quality of the Google Internet index search system,

there are still limitations in the search features.

Which limitations?

201

Internet indexes: Google limitations (Part 1)

• Google does NOT offer/allow

»manual or automatic truncation of words in a query

»manual or automatic stemming of words in a query

202



»a proximity/nearby operator in the queries (such as NEAR)

»full-text searching of complete text in the case of very long documents

»a relevance feedback mechanism

203



»automatic classification/clustering/categorization of retrieved WWW pages, to cope with the problem of the natural ambiguity of meaning of the terms that were used in the search query

»any evaluation of documents retrieved and offered as results

204

Internet indexes: evolution, scalability, sustainability?

• Will one or several Internet indexes (search engines) be able to keep on growing in order to cover a large, interesting part the growing amount of information on the Internet and the WWW with a good retrieval system?In other words, are current systems in this area well scalable and sustainable in an affordable way?

• The answer to this question is not straightforward.

205

Meta- search systems: scheme 1

User

Client computer

+WWW

client program

WWW server

computer

InternetWWW

WWW server

computerswith Internet

search systems

In Out

206

Meta- search systems: scheme 2

UserClient

computer+

Multi-threaded Internet search client program

InternetWWW

WWW server


search systems

In Out

207

Meta- search systems: scheme 1+2

User

Client computer

+WWW

client program

Client computer

+ Multi-threaded Internet search client program

WWW server

computer

InternetWWW

WWW server


search systems

In Out

208

Meta-search systems: vocabulary / synonyms

• “multi-threaded search systems”

• “multiple search systems”

• “multi-search systems”

• “meta-search systems / tools”

• “intelligent search agents”

• “federated search systems”

• “portals” (but this word has more meanings)

• ...

209

Meta-search systems: server-based: scheme

User

Client computer

+WWW

client program

WWW server

computer

InternetWWW

WWW server


search systems

In Out

210

Meta- search systems: relations

User

an Internet meta-search system

Internet search system 1

Internet search system collected database 1

WWW pages

Internet search system 2

Internet search system collected database 2

211

Meta-search systems: server-based or client-based

• Online accessible on a server in the Internet.

• On the client, “meta-search software”.

212Examples

Meta-search systems: server-based systems

• http://www.all4one.com• http://www.bytesearch.com• http://www.cyber411.com• http://www.dogpile.com = http://dogpile.com/ • http://www.go2net.com = http://www.metacrawler.com• http://www.kartoo.com• http://www.mamma.com• http://www.museseek.com • http://www.profusion.com• http://www.search.com• http://www.vivisimo.com = http://vivisimo.com/

http://www.all4one.com/

http://www.bytesearch.com/

http://www.cyber411.com/

http://www.dogpile.com/

http://dogpile.com/

http://www.go2net.com/

http://www.metacrawler.com/

http://www.metacrawler.com/

http://www.kartoo.com/

http://www.mamma.com/

http://www.museseek.com/

http://www.profusion.com/

http://www.search.com/

http://www.vivisimo.com/

http://vivisimo.com/

213Examples

Meta-search systems: server-based systems

• An overview of meta-search systems that are based on a server in the Internet is avialable via

http://directory.google.com/Top/Computers/Internet/Searching/Metasearch/

214Example

Meta-search systems: server-based: example: Vivisimo

215Example


216Example


• Vivisimo adds value by analysing the retrieved results / hits / links / WWW documents, in order to cluster / group / categorize / classify / map these under headings / classes / categories, to make further selections by the user / searcher easier and faster.

• Vivisimo can accomplish this on the fly, that is WITHOUT pre-processing the documents before the search.

217Example


• In the test search for a family name, Vivisimo succeeded in clustering documents related to different persons with the same family name.For comparison: the clustering search engine Teoma did not accomplish this.

218Example

Meta-search systems: server-based: example: Dogpile

• The clustering software of Vivisimo is also used on other systems.

• Example: http://dogpile.com/

http://dogpile.com/

219Example

Meta-search systems: server-based: example: Kartoo

220Example

Meta-search systems: server-based: example: Kartoo

• Kartoo offers an advanced graphical user interface.

• Before you can exploit the system, reading the manual is recommended.

221

Meta-search systems: client-based: scheme

UserClient

computer+

Multi-threaded Internet search client program

InternetWWW

WWW server


search systems

In Out

222Examples

Meta-search systems: client-based: example

Example:

Copernic http://www.copernic.com

http://www.copernic.com/

223

Meta-search systems: advantages (Part 1)

+ Saves time when otherwise more than only 1 Internet-based information source would have to be used one after the other; for instance when searching for specific information that is hard to find in any single source.In other words: for the same time spent, more sources can be covered.

+ Only 1 user interface must be learned for many sources.

224


+ The user interface of some meta-search systems can be adapted to the local user population, which is cannot be realised with most external, Internet-based information sources.

+ In comparison with systems that first integrate/merge the information from several sources into one source and afterwards provide access, meta-search systems provide more up-to-date access to the information.

225


+ Some meta-search systems provide a useful integration of the results they get from the various primary search systems, with a removal of repeated results.

226


+ Some server-based and client-based meta-search systems show links among retrieved pages.

+ Some client-based meta-search systems allow storage on the client computer of a search query for later, repeated usage/application; application of such a system even allows excluding resulting documents that were already retrieved in an earlier search.

227


+ Can add value, for instance by analysing the results / hits so that they can be clustered / grouped / categorized / classified, to make further selections by the user / searcher easier and faster.Example: http://www.vivisimo.com

http://www.vivisimo.com/

228

Meta-search systems: disadvantages (Part 1)

- It is not always clear through which Internet indexes the meta-search system will search.

- Not all meta-search systems can search all the major primary search systems; for instance the famous Google Internet index is normally NOT included.

- The systems are often slower than a direct, primary search system.

- Only a limited number of the results that can be obtained from the various Internet indexes are shown.

229

Meta-search systems: disadvantages (Part 2)

- Some specific or advanced features of the individual search systems cannot be used through all the meta-search systems, such as:

»Boolean searching,

»proximity searching,

»field searching,

»categorization / clustering of search results,

»...

230

Internet information sources

Coverage of Internet directories and Internet indexes

A global Internet index

A global Internet directory

231

Global Internet search tools: a comparison

Global Internet directories

• Only a limited selection of Internet sources

• Browsing information sources is easy

• Good for broad searches

Global Internet indexes

• About 1/3 of the Internet is covered by an index

• Searching requires some skills and knowledge

• Good for specific, narrow searches

Multi-threaded search systems

• These get information from directories and indexes

• Searching requires some skills and knowledge

• Good when even 1 index does not yield information

232

Internet indexes cover only a part of the Internet: introduction (1)

The “visible” part of Internet

The “hidden, invisible” part of Internet and the WWW, (that is not searchable using a global index

like Alltheweb, AltaVista, Google...)

233

?? Question ??

Which information on the Internet is not covered

by many searchable Internet indexes?

Which information on the Internet is not covered

by many searchable Internet indexes?

234

Internet indexes cover only a part of the Internet: introduction (2)

Why can Internet indexes find only a part of what is in fact available through the Internet?

1. Quantitative technical limitations: Each Internet search system has indexed only a part of the static WWW pages that are available for indexing.

2. Qualitative technical limitations: Besides the static WWW pages that Internet search engines try to cover, many other, quite different sources exist, that are also available through the Internet, but that are not incorporated in those search engines.

235

Internet

Internet indexes cover only a part of the Internet: scheme

WWW

Databases and

file archives accessible through

the Internet

telnetftp...

telnetftp...

CGI, ASP,...CGI, ASP,...

Rapidly changing information, such as news

Information accessible only when passwords are used

Static indexable texts in the WWW( = on HTTP server computers)

covered partly by Internet indexes

Wordfiles

PDFfiles

236

Database accessible over the Internet: a famous example: Medline/PubMed

Example

237

Internet indexes cover only a part of the Internet: conclusion for users

When you want to retrieve information about a particular subject from the Internet, use not only WWW indexes, but use also other sources accessible through the Internet

»databases! (book and journal bibliographies, library catalogues, archives of group messages, directories, atlases,…)

»rapidly changing information, such as news

» information accessible only when passwords are used

»anonymous ftp file archives

»e-mail based interest groups; Usenet newsgroups

238

Gateways to Internet databases accessible free of charge

• Most Internet search engines search classical, static WWW pages and not databases accessible through the WWW.

• However, some systems offer a gateway to search databases on the Internet. Examples:

»http://www.completeplanet.com/

»http://www.invisible-web.net/

(See also other more general directories/overviews/lists of Internet information sources.)

http://www.completeplanet.com/

http://www.invisible-web.net/

239Example

Gateways to Internet databases accessible free of charge: screenshot

240

Internet: who owns the search tools?

In 2003:

• The company Yahoo! owns

» the most famous global Internet subject directory

»3 (!) Internet full-text search engines: All the Web, AltaVista, Inktomi

• The company Google owns

» the most famous Internet full-text search engine

»one of the best Internet image search engines

»a gateway to old and new Usenet news messages

241

Current awareness services focusing on WWW pages: introduction

• Tracking changes in one or more public access pages on the WWW or finding new pages, is possible in an automated way,

»by using one of the available, suitable, programs loaded on your client workstation! example: the advanced version of Copernic that is not available free of charge

» through “alert” services based on a server on the WWW

—that track updates for the user/subscriber

—and send alerts by email to the user/subscriber

242

Current awareness services focusing on WWW pages: modified versus new

• Several systems exist that can track changes / modifications / updates in a particular existing WWW page for you, even free of charge.

• Some systems can find new pages on the WWW for you.

243

Current awareness services focusing on WWW pages: Google Alert

• Can discover relevant changed or new WWW pages for you in the future.

• Is based on the external Internet index Google.

• Works with search queries given by you that are stored on their server computer.

• Free of charge.

• http://www.googlealert.com/

Example

http://www.googlealert.com/



244

Current awareness services focusing on WWW pages: Google Alert

Example

245

Current awareness services focusing on WWW pages: directly from Google

• Since 2004.

• Can discover relevant changed or new WWW pages for you in the future.

• Is based on the popular Internet index Google.

• Works with search queries given by you that are stored on their server computer.

• Free of charge.

• Available at http://www.google.com/ and then see the page with additional services.

Example


246



Public access book databases

247

Public access book databases: introduction

Public access book databases: introduction

• Even in this age of Internet-based information sources, a lot of information is still distributed in the form of printed books.

• The contents of most books is (still) not available on the Internet.

• Most general Internet search tools do NOT allow you to find out about the existence of books that may be interesting for you.

• So, specific search tools to find books can be useful.

248

Public access book databases: an overview

Public access book databases: an overview

• (Databases by publishers.)

• Fee-based databases by commercial providers

• Databases by book distributors / bookshops!

• Online public access catalogues of

» local libraries,

»national libraries (which produce and offer normally their national bibliography)!

»big, famous libraries!!

• (Databases of computer-based versions of books.)

249

Public access book databases: which one to use?

Public access book databases: which one to use?

• For years, the market of bibliographic information on books was limited to the services and databases of subscription-based bibliographic providers.

• Nowadays, the WWW provides a key to unlock many possibilities to find bibliographic information.

• Which book database should be preferred for particular applications is not clear for most librarians or end-users.

250

Suitable book databases?

AIM RECOMMENDED SYSTEMS

To find book titles about a specific subject / topic

?

To find book titles published before 1990

?

To find a book title through a title search

?

To find the price of a book

?

To be informed regularly about new books

?

251

Public access book databases by commercial producers

Public access book databases by commercial producers

• To find currently available books, some databases assembled by commercial producers can be interesting.

• Example: Global Books in Print

• These databases offer formal descriptions of books, prices of the books, short descriptions of the contents with subject terms…

• However, access to such a database is not free of charge and can be expensive (in comparison with alternatives).

252

Public access book databases provided by bookshops

Public access book databases provided by bookshops

• To find currently available books, the bibliographic databases assembled by big bookshops are interesting.

• Several offer a good coverage and are accessible free of charge.

• The added price information can be useful for the acquisition and accounting department of a library or if an individual user wants to buy a book.

• Some provide a current awareness service, also free of charge.

253

Book databases accessible free of charge: examples in U.S.A.

Book databases accessible free of charge: examples in U.S.A.

• Amazon.com (US):http://www.amazon.com/ http://www.amazon.co.uk/ note: amazon, NOT amazoneSubject description is poor.Allows full text searching in the contents of a selection of recent books, fre of charge.

• Barnes and Noble (US):http://www.bn.com/

Examples

http://www.amazon.com/

http://www.amazon.co.uk/

http://www.bn.com/

254

Book databases accessible free of charge: examples in Europe

Book databases accessible free of charge: examples in Europe

• Blackwell’s on the Internet (International, academic books):http://www.blackwell.co.uk/

• VLB for books in Germanhttp://www.buchhandel.de/

• For books in Frenchhttp://www.chapitre.com

• Boeknet - De Nederlandse Internet Boekhandel (Dutch)http://www.boeknet.nl/

Examples

http://www.blackwell.co.uk/



http://www.buchhandel.de/

http://www.chapitre.com/

http://www.boeknet.nl/

255

Book databases accessible free of charge: for old books

Book databases accessible free of charge: for old books

To find used, secondhand, rare, hard-to-find, and out-of-print books around the world:abebooks http://www.abebooks.com/

Examples

http://www.abebooks.com/



256

Free public access bibliographic book database + price comparisons

Free public access bibliographic book database + price comparisons

• Even comparisons of the catalogues of shops of books (as well as of music, movies and many other goods) are available free of charge.

• See for instance

»http://www.bookfinder.com/

»http://www.dealtime.com/

http://www.bookfinder.com/



http://www.dealtime.com/

257

Example of an international public access dissertation database

Example of an international public access dissertation database

• The dissertation database of UMI is available from: http://wwwlib.umi.com/dissertations/

• The most current two years are available without charge.

Examples

http://wwwlib.umi.com/dissertations/

258

Databases of links to the full text of many books

Databases of links to the full text of many books

Databases (accessible free of charge ) of links to the full text of many books:

• http://digital.library.upenn.edu/books/

• http://wordtheque.com/

Examples

http://digital.library.upenn.edu/books/

http://wordtheque.com/

259

Collection of links topublic access book databases

Collection of links topublic access book databases

• See for instance Internet directories like Yahoo! that lead to information about books.

Examples

260

Online Public Access Catalogues of libraries

Online Public Access Catalogues of libraries

• Mainly to find older books, the catalogues of libraries can be useful.

• Most are accessible online and free of charge.

261

Online Public Access Catalogues = OPACs: definition

Online Public Access Catalogues = OPACs: definition

Online Public Access Catalogue:

a term used to describe any type of computerized library catalog offered to the public by online login

262

Online Public Access Catalogues of the big famous libraries

• For instance: Library of Congress (USA)

• Their coverage is good.

• They offer the best subject descriptions.

• Access is free of charge.

• So they form excellent sources to find books about a particular subject/topic.

263

Online Public Access Catalogues:The British Library

Online Public Access Catalogues:The British Library

• Accessible online via WWW: Since 2000: http://blpc.bl.uk/

• Access free of charge

Example

http://blpc.bl.uk/

264

Online Public Access Catalogues:The British Library: screenshot

Online Public Access Catalogues:The British Library: screenshot

Example

265

Online Public Access Catalogues:catalogues of national libraries

Online Public Access Catalogues:catalogues of national libraries

• National libraries are first of all an outstanding source for the local publications.

• The national libraries are the most reliable source for bibliographic searching and verification.

266

Online Public Access Catalogues:union catalogues of libraries

Online Public Access Catalogues:union catalogues of libraries

• Some systems offer access to the merged catalogues of several libraries, so-called ‘union catalogues’.

• Example: Copac http://www.copac.ac.uk/ is accessible free of charge.

http://www.copac.ac.uk/

http://www.copac.ac.uk/

267

Public access book databases: evaluation criteria - desiderata (1)


• Is usage free of charge?

• Wide coverage? Specialized coverage of books

» in your preferred language?

»on particular subjects / topics?

»published in a specific country?

»published in a particular time period?

»of particular types (such as conference proceedings)?

• Up to date? Frequent updates?

268



• Does the database offer besides each formal book descriptions also

»an abstract / summary / description of the contents?

»a table of contents?

»the price?

»information about the publisher?

»titles of related books?

»reviews by readers?

269



• Full text indexing of each item (book description) in the database, so that full text searching is possible?

• Field indexing, so that searching limited to the contents of a particular field is possible? for instance

» the title

» the date of publication

» the author

» the publisher

» the language

270



• Does the database producer improve retrieval by

»adding subject terms, or

»by classifying the books in categories

271



• Powerful search options:

» truncation of words in a query?

»stemming of words in a query?

»Boolean search combinations? combined field searching?

»proximity searching?

»spelling check of your search terms?

»suggestions by the system of spelling variations of the words in the query

» translation of your search terms in several other languages?

272



• Can the user browse through subject categories that are used in the book database?

• Is a user interface offered in your own language?

• Easy user interface?

• Relevance ranking of results?

• Possibility to combine Boolean retrieval with relevance ranking of results?

• Can results be limited to a certain time period?


273



• Can the results be ordered according to date, size, origin...?

• Good presentation of each result?For instance: Are search terms highlighted?

• Can search results be downloaded, well structured with field tags? (For instance to allow incorporation of the data in another database.)

274



• Does the system offer a current awareness service, sending information on new titles that may be of interest to you?

275



• Are other services offered from the same site or with the same interface? Is the system integrated with other services?Additional services can be

»searchable databases of videos, of music CD’s, CD-ROMs, DVDs, all for sale also



276



• Is the database system accessible through the Z39.50 Internet database search and retrieve protocol? In other words, is the database Z39.50 compliant?This would offer the following advantages:

»The system can then be searched starting from one of the available Z39.50 client software packages.

»The database can be then searched simultaneously with other Z39.50 compliant databases and the results from the various databases can be merged. This is useful for rare, uncommon, special items that are difficult to find.

277

Recommended book databases

AIM RECOMMENDED SYSTEMS

To find book titles about a specific subject / topic

Library of Congress, British Library, (Amazon)

To search for book titles published before 1990

national libraries, Barnes&Noble, Infoball, Alapage, Abebooks

Book title search in general

Library of Congress, British Library, Infoball

To find the price of a book

Global Books in Print, Infoball, online bookshops

To be informed regularly about new books

Amazon, Alapage, Bol

278

General conclusion concerning book databases

The

one and only, international, complete, ideal,

bibliographic database

does NOT exist,

but the united forces of the different available book databases should be satisfying.

279



Fee-based online public access information services

280


• A lot of the information on the Internet is available free of charge, but another part is only accessible when a fee is paid to the producer and / or the distributor.

• The first commercial computer systems that make information available online were born around 1975. Most of them are now also available through the Internet.

• Some organisations pay these fees for some sources and then organise access, so that the members of the organisation can retrieve and exploit the information as if it is free of charge.

281




282

Types of online access information systems: “free” for members only



Fee-based online information services, made accessible “free of charge”

by an institute to its members

283

Fee-based online access services: examples (Part 1)


Location of the computer(s)

U.S.A.U.S.A.U.S.A.U.S.A.U.S.A., Taiwan, UKSwitzerlandU.S.A.U.S.A.

Name

America On LineOCLCOvid TechnologiesCompuServeCambridgeData-StarDialogEBSCO

Examples

284



Location of the computer(s)

U.S.A.

U.S.A.U.S.A.U.S.A., The Netherlands,...Germany - U.S.A. - JapanThe Netherlands...

Name

Elsevier ScienceDirect FactivaISI (Web of Knowledge, JCR,…)LexisNexisMSN (Microsoft)ProdigySilver PlatterSTN Swets-Blackwell (e-journals)...

Examples

285

Online information services: various names for similar systems

Online information services: various names for similar systems

• (fee-based) online (access) information service

• (fee-based) online (access) computer service

• databank

• database vendor

• host computer

• aggregator

• ...

286

Online information services: access methods

Online information services: access methods

• Using generic, common communications software

» through the telephone network (telephone + modem)

» through X-25 data communication networks

» through Internet, using client-server systems:

—telnet

—WAIS or Z39.50

—http (WWW)! (Examples: http://www.dialogweb.com; http://www.datastarweb.com)

• (Using client software dedicated to the particular service)

http://www.dialogweb.com/

http://www.datastarweb.com/

287

Online information services:total size of their databases

Online information services:total size of their databases

In 1999:

The big host systems and the public access WWW pages offer a comparable quantity of information:

• WWW offered about 8 terabytes (= 8 000 gigabytes) of text data

(according to Lawrence and Lee Giles, Nature, 1999, Vol. 400, pp. 107-109.)

• Dialog offered about 9 terabytes (= 9 000 gigabytes) (in 1998)

»6 billion pages of text

»3 million images

288

Database hosts / distributors:evaluation criteria - desiderata (1)


• Contract not required?

• A priori payment not required?

• Satisfactory stability / history / evolution / future of host?

• Low costs of data communication?

• Many databases available?

• Whole records available (or only parts)?

• Frequent updates?

• Whole database available? As one file or fragmented?

289



• Low price of access? Low price of information?

• Good searching facilities? (cfr. desiderata for Internet indexes)

• Can the indexes of more than one database be searched simultaneously?

290



• Online indication of costs?

• Practice free of charge?

• Good manuals, documentation and online help?

• Training courses available? Quality?

• Good help desk available?

• Gateway service offered?

• ...

291

Databases of online public access databases

Databases of online public access databases

• Example

»Gale directory of databases !

• Their coverage:

»online access databases

»(databases accessible on CD-ROM)

»...

292

Databases of databases: Gale

Databases of databases: Gale

• Produced in U.S.A.

• Not free of charge

• Available in various formats:

»printed

»on CD-ROM

»online via the host systems Data-Star, Dialog, with a payment required for each use

»online through the Internet through various hosts,for a fixed price per year to be paid in advance

293



Online access databases about journal articles

294

Online access databases about journal articles: overview

Online access databases about journal articles: overview

• Thousands of fee-based online access databases offer bibliographies or full-texts of journal articles in particular subject domains and published by many publishers.

• Many publishers offer searchable bibliographies, but only of their own publications. (for instance Emerald, Elsevier)

• Only few large databases offer access to bibliographies of articles published in journals from many publishers, free of charge.

295

Online access databases about journal articles: Ingenta (1)


• Ingenta Journals allows you to search a bibliographic database of millions of journal articles, including titles, authors, in many cases abstracts.

• Searching is free of charge.

Example

296



• Payment is required to receive the full text of an article.

• Available from

»http://www.ingenta.co.uk/

»http://www.ingenta.com/

• Ingenta has acquired Uncover in 2000.

Example

http://www.ingenta.co.uk/



http://www.ingenta.com/

http://www.ingenta.com/

297

Online access databases about journal articles: Article@INIST

Online access databases about journal articles: Article@INIST

• Article@INIST allows you to search in a bibliographic database, NOT full-text, (Journal articles, journal issues, books, reports, conferences, doctoral dissertations) at the Institut de l'Information Scientifique et Technique, France.

• Does not offer usage of classification or thesaurus.

• Searching is free of charge.

• Available from http://form.inist.fr/public/eng/conslt.htm

• Payment is required to receive the full text of an article.

Example

http://form.inist.fr/public/eng/conslt.htm



298

Online access databases about journal articles: Infotrieve

Online access databases about journal articles: Infotrieve

• Infotrieve allows you to search free of charge in a bibliographic database of the articles of more than 20 000 journal titles and conference proceedings, NOT full-text.

• Available from http://www3.infotrieve.com/

• Payment is required to receive the full text of a document.

• Current awareness services are also offered free of charge: the table of contents of new issues of the journals that you have selected are sent to you by email.

Example

http://www3.infotrieve.com/

299

Online access databases about journal articles: Scirus

• This is a specialised Internet index that allows you to search for selected scientific information (only) on the WWW. This includes the peer-reviewed articles in the journals that are published in ScienceDirect by Elsevier.

• An article can be downloaded in full-text format only when a fee has been paid to the publisher

• The search interface: http://www.scirus.com

Example



300

Online access databases about journal articles: Scirus features

• Offered free of charge by Elsevier.

• Is partly based on the Fast WWW search system that is also used by Alltheweb.

• Offers access to information ordered according to some classification system / taxonomy.

Example

301

Online access databases about journal articles: Medline

Online access databases about journal articles: Medline

• Medline produced by the National Library of Medicine (USA) allows searching a bibliographic database of articles in the field of medicine.

• free of charge

• available from many sites, including

»PubMed of the National Library of Medicine (USA) and

»Ingenta

Example

302

Online access databases about journal articles: Medline through PubMed

Online access databases about journal articles: Medline through PubMed

Example

303

Online access databases:Web of Knowledge

Online access databases:Web of Knowledge

• The Web of Science or more recently the Web of Knowledge offers access through the WWW to a database of bibliographic descriptions of scientific journal articles in all subject domains.

• This database is (only) available to members of organisations / institutes / companies / consortia that pay a yearly, high fee to the producer/publisher of the database.

• This database is not only suitable for subject searching, but also for citation searching.

304



Electronic newsletters and journals

305

Electronic newsletters and journals: introduction

Electronic newsletters and journals: introduction

Since the end of the 1990s, electronic journals have become a new communication medium that cannot be neglected.

Author / Sender Editor Reader / Receiver

306

Electronic newsletters and journals: variations on a theme

• We can distinguish several methods

»of distribution and access

»of formatting the information (PDF, HTML,…)

»of pricing and licensing

»of restricting access (authentication and authorization of legitimate users)

»to integrate access to e-journals with access to other information sources

307

Electronic newsletters and journals: various types and the price of accessElectronic newsletters and journals: various types and the price of access

• We can distinguish various types:

»equivalents of a version printed on paper

—published almost simultaneously

—print version published long time before electronic version = deliberate long delay for the electronic version

»purely electronic publications

• Price of access: from free of charge to very expensive

308

Electronic newsletters and journals: access and distribution methods

Electronic newsletters and journals: access and distribution methods

Many different methods are used:

»anonymous ftp

»gopher

»WAIS / Z39.50

»electronic mail, listserv,...

»Usenet News

»loaded on local systems in universities or institutes

»http, WWW !

»Open Archives Harvesting Protocol + http, WWW

309

Electronic newsletters and journals through the WWW

Electronic newsletters and journals through the WWW

• The WWW has become the most important platform for access to electronic newsletters and journals.

310

Electronic newsletters and journals: problems and challenges

• There is no central database with all article titles, summaries, and full contents. There is not even a central, complete and up to date directory of journal titles.

• There is no standard licensing/pricing method.

• Not all electronic journals are accessible through 1 user interface.

• Many passwords must be used.

• Archiving (By whom? Forever?)

311

Electronic newsletters and journals: integration with other sources

It is not (yet) clear and straightforward how electronic journals should be integrated

»in a library collection

»in a library web site

»in the catalogue database

»in interlibrary lending (depends on licensing agreement for each individual journal)

312

Electronic newsletters and journals: integration and access methods

Access can be possible through

»A gateway offered by a subscription agent or the publisher

»A commercial bibliographical database

»A web-based static listing of journal titles

»A web-based OPAC (for instance in the MARC 856 field)

»A local searchable database for e-journals

»Special linking mechanisms, based on OpenURL (for instance SFX commercialised by Ex Libris orVLINK commercialised by GEAC)

COMPLEXITY

313

Electronic newsletters and journals: more than one access method

• How should libraries and readers/users cope with the fact that many e-journals can be accessed in more than one ways, that is by hyperlinks starting from various information systems or services, while authentication and authorization is NOT fully automated for all those systems, once that a licensing agreement has been established?

• What mechanisms can offer support for this situation?

• This is called the “multiple copy problem” or the “appropriate copy problem”.

314

Link resolver to guide users to the appropriate e-document: introduction

• Link resolver = appropriate hyperlink generator: to guide users to the most suitable electronic sources that are appropriate for the specific library or specific user, for instance to cope with the multiple-copy / appropriate copy problem (such as SFX software from Ex-Libris or V-link software from VUBIS-GEAC)

315

incoming reference target information

sourceappropriate hyperlink generator

Link resolver to guide users to the appropriate e-document: scheme

database about local situation“Knowledgebase”

316

!! Task - Assignment - Problem !!

Find out how you can efficiently access electronic journals

from your institute.

Find out how you can efficiently access electronic journals

from your institute.

317

Directory of Open Access Journals

• The Directory of Open Access Journals is a directory of electronic journals that can be accessed free of charge.

• Available since May 2003.

• http://www.doaj.org/

http://www.doaj.org/



318

Directory of Open Access Journals: screenshot

319



Finding multimedia files on the Internet

320

Finding multimedia files on the Internet: introduction

Several public access search systems are available free of charge, to search the Internet for multimedia files:

»images / pictures (either artwork, either photos, or both)

»sound / audio files (music, speeches...); video

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Finding images on the Internet:introduction

• Several public access search systems are available free of charge to search for images / pictures (either artwork, either photos, or both) on the Internet.

• When searching for images, the search results from such a system offer not only links to the image files on the Internet, but also directly small versions of the images (so-called “thumbnails”).

322 Examples

Finding images on the Internet:screen shot of a Google image search

323Examples

Finding images on the Internet:examples of search engines (1)

• http://alltheweb.com/

• http://gallery.yahoo.com/

• http://images.google.com/ ! or via http://www.google.com/The largest database in this category (at least in 2002, 2003, 2004). For each result, not only a thumbnail is offered, but also directly the origin with the readable URL; this makes it easier to guess the relevance of the document.




http://gallery.yahoo.com/



http://images.google.com/






324Examples


• http://multimedia.lycos.com/

• http://www.altavista.com/ (also audio and video, choose not the normal text search, but IMAGES in the user interface.)

http://multimedia.lycos.com/






325Examples


• http://www.ask.com/ or http://www.aj.com/ or http://aj.com/ Ask Jeeves.Offers no indication of the number of images retrieved, which is a disadvantage when many pictures are found, but only a few can be seen at the time.

http://www.ask.com/

http://www.ask.com/

http://www.ask.com/

http://www.aj.com/

http://www.aj.com/

http://www.aj.com/

http://aj.com/

http://aj.com/

http://aj.com/

326Examples


• http://www.ditto.com/

• http://www.picsearch.com/ Does NOT directly show the origin of each picture with a readable URL, together with each thumbnail.

http://www.ditto.com/



http://www.picsearch.com/

327Examples

Finding images on the Internet:directories of search engines

A collection of links to suitable Internet search engines:

http: //directory.google.com /Top /Computers /Internet /Searching /Search_Engines /Specialized/Images/

http://directory.google.com/Top/Computers/Internet/Searching/Search_Engines/Specialized/Images/





328Example

Finding audio on the Internet: example of a search engine

• http://www.findsounds.com

• Allows you to find sound files in formats aiff, au, wav.

http://www.findsounds.com/

329Example

Finding audio and video on the Internet: example of a search engine

• http://www.altavista.com/ (use the special multimedia finder)


330Examples

Finding audio and video on the Internet: directories of search engines

A collection of links to suitable Internet search engines:

http: //directory.google.com /Top /Computers /Internet /Searching /Search_Engines /Specialized /Multimedia/

http://directory.google.com/Top/Computers/Internet/Searching/Search_Engines/Specialized/Multimedia/





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Evolution and future trends

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Online access information: evolution and future trends

• An increasing amount of information becomes available online.

• A growing amount of this online information becomes available free of charge.

• The quality and ease of use of software on server as well as client is growing.

A consequence is:

• An increasing number of end-users searching for information online.

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Online access information: easier and more complicated?!

• At the same time, information retrieval becomes both easier and also more complicated.This may seem strange and contradictory, but it is reality.

This is a paradox.

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Online access information: easier information retrieval systems

• Individual information retrieval systems become easier:

»they react faster;

»they can provide access to more data/information in one action;

»their user interfaces are simple, but more sophisticated, intelligent retrieval algorithms can nevertheless deliver satisfactory results in most simple cases.

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Online access information: more complicated information market

• The whole information landscape consists of more and more decentralised information sources, each one bringing an individual user interface that should be mastered. Making the right, ideal choice among the sources becomes not easier, perhaps even more complicated every day.

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Online access information: more complicated information market

• Furthermore, for many sources the accessibility / availability, the user interface, the interlinking, depend on the organisation in which the searcher is active.

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Online access information: conclusion

• In the case of simple information needs, the WWW and the search tools can work like “magic”.

• However, in the case of more complicated information needs, there is still is no “magic button” that brings you immediately to all the required information.

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•These slides should be available through the WWW from http://www.vub.ac.be/BIBLIO/nieuwenhuysen/presentations/

•References to publications about this subject and more slides are available through the WWW fromhttp://www.vub.ac.be/BIBLIO/nieuwenhuysen/courses/

(note: BIBLIO and not biblio)




http://www.vub.ac.be/BIBLIO/nieuwenhuysen/courses/

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