1 Online access information sources and services Introduction

1

Online access information sources and services

Introduction

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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.

3

Online information sources: prerequisites

Before using online accessible information sources, you should ideally have some knowledge and skills related to

• computer hardware

• computer software

• the Internet

• the WWW

• the concept of ‘information’

• information retrieval in general

• the information market

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Discovering online access information sources

Equipment and tools required:

»A microcomputer

»Data communication facilities

»Tools to locate information sources

»Some knowledge and skills

»...

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Growing importance of computer network information resources

• Networked information resources are growing at a high rate, not only in volume but also in importance. There are many sources there which are vital to research and many others which are useful generally.

• To keep abreast of their field, most academics and researchers will find an increasing need to use the network for fast and efficient communication and for access to information. If they don’t, they are likely to be left behind, because most of their colleagues in institutions around the world will be doing just that.

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Online access to information: avoid network traffic jams

To access from Europe online information sources in the US, work when lines are not saturated.

(better in the morning than in the afternoon)

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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.

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• 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.

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

In 2001:

• More than 1 000 million unique URLs in the total Internet

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

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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

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Types of online accessinformation systems

We can categorize the various online accessible information systems in various ways:

»primary or secondary

»based on information contents that is offered

»online access method required (= communication protocol)

»freely accessible versus accessible for a fee

»computer file format

(Of course these categorizations are normally not independent but related.)

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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”, ...

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!? Question !? Task !? Problem !?

Do you know examples of primary and of secondary

online information systems?

Do you know examples of primary and of secondary

online information systems?

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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)

• ...

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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

• ...

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

• 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.

• 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.

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Public access information sources free of charge

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

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

Public access information sources free of charge

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

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

by an institute to its members

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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

»…

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WWW sites classified by contents

• Commercial: about 80%

• Other 20%:

»Science and education

»Personal

»others

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

others20%

Commercial80%

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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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WWW sites classified by language

• English: about 87%

• Other languages: 13%

in 1999

other languages

13%

English87%

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Internet-based encyclopedias

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Encyclopedias accessible through Internet and WWW

• 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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Encyclopedias accessible through Internet and WWW: examples

• Encarta Concise Free Encyclopedia

»http://encarta.msn.com/

• 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://encarta.msn.com/

http://www.britannica.com/

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

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Encyclopedias accessible through Internet and WWW: examples

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

»http://thecanadianencyclopedia.com/

Example

http://thecanadianencyclopedia.com/

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Encyclopedias accessible through Internet and 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

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Internet search functions built in browser software

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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

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The Internet search button of browsers: introduction

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

Netscape, Microsoft Internet Explorer

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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.

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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.

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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.

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Get some experience in using the address form of your web browser program

to search for documents on a particular subject that are available on the WWW.

Get some experience in using the address form of your web browser program

to search for documents on a particular subject that are available on the WWW.

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Searching with browsers using the address form: comments

+ An advantage is the ease of use.

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

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Internet directories and indexes

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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)

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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)

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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!

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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.

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Internet global subject directories: limitations

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

• 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.

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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.

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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/

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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

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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 (not produced by Yahoo!) 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

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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/

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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/

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Internet global subject directories: BUBL for marine biology

Example

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Internet global subject directories: Google directory

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


• Very similar to the Open Directory Project.

Example

http://directory.google.com/

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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/

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Internet global subject directories: LookSmart

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

• Links are offered to LookSmart by the Internet index AltaVista.

• A search in the LookSmart index is also executed with the Internet index AltaVista.


Example

http://www.looksmart.com/

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Internet global subject directories: Magellan

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


Example

http://magellan.excite.com/

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Internet global subject directories: Open Directory Project

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


Example

http://www.dmoz.org/

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Internet global subject directories: Point (Communications)

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


Example

http://www.pointcom.com/

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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/

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Internet global subject directories:lists of directories

• Many Internet global subject directories exist, but the ideal one is not available.

• Overviews / lists of Internet subject directories exist also.

• Examples (accessible free of charge):

»http://www.surfnet.nl/

»http://searchengineshowdown.com/dir/

http://www.surfnet.nl/

http://searchengineshowdown.com/dir/

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Internet global subject directories:using more than one at the same time

• A system allows you to use several European Internet subject directories at the same time.

• This is available free of charge throughhttp://www.renardus.org/

http://www.renardus.org/

http://www.renardus.org/index.html

http://www.renardus.org/index.html

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Try to find Internet sourceswhich are relevant for you, by using an Internet-based

global subject directory.

Try to find Internet sourceswhich are relevant for you, by using an Internet-based

global subject directory.

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Internet global subject directories: evaluation criteria (Part 1)

• Is 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?

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

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• Easy user interface?

• Short response times?

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

• Good presentation, description of each site?

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

• Is translation of documents offered free of charge?

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• Good documentation and online help?

• Good help desk available?

• High stability and reliability?

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• 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

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

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

»auctions through WWW

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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

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

• Computer science & engineering: http://www.ub.lu.se/eel/

• Social sciences: http://www.sosig.ac.uk/

• Marine science and oceanography: http://oceanportal.org/

Examples

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



http://www.sosig.ac.uk/



http://oceanportal.org/

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• Medicine and healthcare: general:

• http://www.achoo.com/

• http://www.medscape.com/

• http://www.omni.ac.uk

• Medicine and healthcare: General pediatrics:

• http://GeneralPediatrics.com

• http://www.medscape.com/pediatricshome

• http://www.pedinfo.com/

Examples

http://www.achoo.com/



http://www.medscape.com/



http://www.omni.ac.uk/

http://generalpediatrics.com/

http://www.medscape.com/pediatricshome

http://www.medscape.com/pediatricshome

http://www.pedinfo.com/



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• Engineering: http://www.eevl.ac.uk/

• Civil engineering: http://www.icivilengineer.com/

• Fishing: http://www.onefish.org/

• Art, architecture and the media: http://www.adam.ac.uk/ or http://adam.ac.uk/

Examples

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



http://www.icivilengineer.com/



http://www.onefish.org/



http://www.adam.ac.uk/



http://adam.ac.uk/

http://adam.ac.uk/

http://adam.ac.uk/

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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.

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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

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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

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Internet indexes:AltaVista

Example

The primary search interface can be found in the US:

http://www.altavista.com/

http://www.av.com/

(These addresses all lead to the same information.)

Mirror site in UK:

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


http://www.av.com/

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

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Internet indexes:AltaVista: features

• Allows full text searching of the WWW

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

• Offers relevance ranking of search results

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

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

Example

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Internet indexes:AltaVista simple versus advanced

• “Simple” is suited for instance for searches

»with only 1 concept expressed as a series of synonyms, narrower terms,...such as a search for a person, a company, an institute,...

»when ranking is important

• “Advanced” is suited for instance for searches

»with more than 1 concept so that an AND combination is useful, besides an OR combination

»when ranking is not important

Example

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Internet indexes:Fast = All the Web

Example

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

• You can search the WWW and ftp servers.

• The database is one of the biggest.

http://www.alltheweb.com/

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Internet indexes: Google (Part 1)

• You can search for WWW pages at http://www.google.com/

• Does NOT offer/allow

»full Boolean searches

»manual or automatic stemming/truncation

Example

http://www.google.com/

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Internet indexes: Google (Part 2)

• 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

• Searches include full text searching of files on the WWW; not only html pages, but also files in the formats Adobe PDF, Microsoft Word, Microsoft Excel, Microsoft PowerPoint, Rich Text Format,…

Example

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Internet indexes: Google additional features

Besides a system to search for WWW pages, Google offers also »a subject directory»searching for images on the WWW

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

• Thus Google has become a great integrator / aggregator.

Example

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Make a search with Google.Make a search with Google.

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Internet indexes: Hotbot

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

• You can search the WWW

• Based on an Internet index created by Inktomi.

• Allows advanced, Boolean searching.

Example

http://www.hotbot.com/

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Internet indexes: Lycos

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

• Has been based on various databases of WWW pages over time.In 2001-2002: based on the Fast database of WWW pages, that forms also the basis for the search system Alltheweb.

Example

http://www.lycos.com/

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Internet indexes: MSN Web Search

• The search interface can be found with the search functions build into Microsoft Internet Explorer and at http://search.msn.com/

• Offered free of charge by Microsoft.

• You can search for Web content.

• Since 1998.

• Is based on an Internet index created by another company.

Example

http://search.msn.com/

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Internet indexes: coverage / size of each index

The indexes grow and their “size ranking” is variable.

Biggest systems in 2002:

• Google !

• AltaVista

• (Fast =) All the Web (serving also Lycos)

• Systems based on the INKTOMI database of WWW pages, such as Hotbot, MSN Web search,…

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Try to find Internet sourceswhich are relevant for you, by using an Internet index.

Try to find Internet sourceswhich are relevant for you, by using an Internet index.

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Develop a suitable search query and apply this with an Internet search engine to find

“general reviews about monitoring seawater pollution”

Some advice: use synonyms, narrower terms, truncation,

and Boolean combinations.

Develop a suitable search query and apply this with an Internet search engine to find

“general reviews about monitoring seawater pollution”

Some advice: use synonyms, narrower terms, truncation,

and Boolean combinations.

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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.)

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the complete WWW

a global Internet index

an index limited to sources in/of a country or region

Internet indexes: non-global, regional systems

91


Which Internet search system is closest to a classical library catalogue:

an Internet subject directory or an Internet index?

Which Internet search system is closest to a classical library catalogue:

an Internet subject directory or an Internet index?

92


Which differences do you see between a classical library catalogue

and an Internet index?

Which differences do you see between a classical library catalogue

and an Internet index?

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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.

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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.

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Internet indexes: evaluation criteria (Part 1)


• 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?

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• 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?

• Does the database system work with a full text indexing of each ASCII and HTML document that has a place in the database, so that full text searching is possible?

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

• 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

»Microsoft PowerPoint

»Adobe Acrobat (Portable Document Format)

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

the HTML title, HTML keywords,

URL, date,

link, Java applet,

text, image file,

sound file, video file,...

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• Does the system offer powerful search options like

»truncation?

»word stemming?

»Boolean search combinations?

»proximity searching?

»automatic translation of your search terms in several other languages?

»spelling check of your search terms?

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• 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?

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

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

• Can the results be ordered according to date



• Can the results be ordered according to size?

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

102


• 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.

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

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

• Good and detailed summary of each result available?

• Offers an analysis of words occurring in the results, which can help you to refine a search?

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• Is translation of documents offered free of charge?

• High stability and reliability? No large variations/fluctuations in the results from identical searches at different times.



• Can the search system provide updated results through electronic mail, as a current awareness tool?

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• Other services available besides the normal WWW index:

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

»anonymous ftp file index?

»gopher index?

»searchable Usenet newsgroups archive?

»Internet subject directory?

»White pages = people finder = addresses = ...



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• 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

107


Why do different Internet search engines (in most cases)

give different results for an identical search?

Why do different Internet search engines (in most cases)

give different results for an identical search?

108

Internet indexes for citation searching: introduction

• Some Internet indexes / search engines allow you to search for documents / pages / URLs that link to a particular page, to some URL that you already know (such as one of the web pages that you have developed or that you have made available yourself).

• Linking to a URL is similar to citing an information source.

• Such search systems can be used to analyse web citations.

• Web citations are sometimes named “sitations”.

109

Internet indexes for citation searching: query syntax

For details about the required query syntax, query formulation, see the online manual or help pages of the search system that you want to use.

110

Internet indexes for citation searching: link versus linkdomain

Do not confuse

• links to a particular web page,using for instance a query like “link:this_page.html” with

• links to a whole web domain, using for instance a query like “linkdomain: this_site”

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Internet indexes for citation searching: examples of systems

• AltaVista !

but note that “Simple search” and “Advanced search” may give different results

• Hotbot

• Google

• (Northernlight !)

by using a query like “link:this_page NOT url:this_site”

Examples

112

Internet indexes for citation searching: applications

• Citation searching on the WWW or on an intranet can be used

»to get an idea of the importance, the fame, the impact of a particular web document, as measured by the number of links/citations to that page

»to find out who has considered a particular page as interesting enough to make a link to

»to find comments/criticisms on a particular web document

113


Use a citation search engine.Use a citation search engine.

114

Internet indexes for citation searching: evaluation criteria (1)


• Is left truncation possible of the URL for which you want to find citations, so that citations to this and to underlying documents can be found in one action?

• Is right truncation possible of the URL for which you want to find citations, so that citations to this and to related documents on multiple sites can be found in one action?

115


• Can self-citations and/or other documents be excluded from the search results in the query used to find citations?

• How complete is the coverage of the citation search system?

• Is the coverage of the search system good or poor for a particular geographic region?

• Is the coverage of the search system good or poor for a particular type of documents?

116


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

• Is some form of relevance ranking of results offered?

• Which criteria are used for the ranking?

• Can the results be ordered according to date



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

117


• Is a good and detailed summary of each result made available?

• High stability and reliability? No large variations/fluctuations in the results from identical searches at different times.



• Can the search system provide updated results through electronic mail, as a current awareness tool?

118


Compare Internet directories with Internet indexes

(collection of data, coverage, ease of use,...)

Compare Internet directories with Internet indexes

(collection of data, coverage, ease of use,...)

119

Multi-threaded Internet search systems: scheme 1

User

Client computer

+WWW

client program

WWW server

computer

InternetWWW

WWW server

computerswith Internet

search systems

In Out

120

Multi-threaded Internet search systems: scheme 2

UserClient

computer+

Multi-threaded Internet search client program

InternetWWW

WWW server


search systems

In Out

121

Multi-threaded Internet 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

122

Multi-threaded Internet search systems: vocabulary

• “multi-threaded Internet search systems”

• “multiple search systems”

• “multi-search systems”

• “meta-search systems”

• “intelligent Internet search agents”

• “Internet meta-search tools”

• ...

123

Multi-threaded Internet search systems: relations

User

an Internet meta-search system

Internet search system 1

Internet search system database 1

WWW pages

Internet search system 2

Internet search system database 2

124

Multi-threaded Internet search systems: server-based or client-based

• Online accessible on a server in the Internet.

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

125Examples

Multi-threaded Internet search systems: server-based

a collection is available from http://www.surfnet.nl/

http://www.all4one.comhttp://www.bytesearch.comhttp://www.cyber411.comhttp://www.dogpile.comhttp://www.gohip.comhttp://www.go2net.com =

http://www.metacrawler.comhttp://www.mamma.comhttp://www.profusion.comhttp://www.search.com

http://www.surfnet.nl/

http://www.all4one.com/

http://www.bytesearch.com/

http://www.cyber411.com/

http://www.dogpile.com/

http://www.gohip.com/

http://www.go2net.com/

http://www.metacrawler.com/

http://www.mamma.com/

http://www.profusion.com/

http://www.search.com/

126Examples

Multi-threaded Internet search systems: client-based

Example:

• Copernic http://www.copernic.com

http://www.copernic.com/

127

Multi-threaded Internet search systems: advantages

+ Saves time when otherwise more than only 1 Internet index would have to be used one after the other; for instance when searching for specific information that is hard to find in any single Internet index.

+ 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.

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

128

Multi-threaded Internet 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.

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

129

Multi-threaded Internet search systems: disadvantages (Part 2)

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

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

»Boolean searching,

»proximity searching,

»field searching,

»categorization of search results,...

130

Internet information sources

Coverage of Internet directories and Internet indexes

A global Internet index

A global Internet directory

131

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

132


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?

133

Internet indexes cover only a part of the Internet: introduction

The “visible” part of Internet

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

like, AltaVista, Google...)

134

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

135


Give an example of a database that is accessible through the WWW.

Give an example of a database that is accessible through the WWW.

136

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

»anonymous ftp file archives,

»e-mail based interest groups; Usenet newsgroups,

»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

137

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://invisibleweb.com/

• http://www.invible-web.net/

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

http://invisibleweb.com/

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

138

Finding multimedia files on the Internet

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

139

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”).

140Examples

Finding images on the Internet:examples of search engines

• http://alltheweb.com !!!

• http://gallery.yahoo.com/ !

• http://images.google.com/ !!!! or through http://www.google.com/

• 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://www.ditto.com/ !

http://alltheweb.com/

http://alltheweb.com/

http://gallery.yahoo.com/



http://images.google.com/






http://multimedia.lycos.com/




http://www.ditto.com/



141 Examples

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

142


Use a specialised search engineto find images

about a particular subject on the Internet.

Use a specialised search engineto find images

about a particular subject on the Internet.

143


When you want to know if the contents of a particular WWW page

has changed, then you can of course

check/read/visit that page regularly.

But is there a simpler way to track changes?

When you want to know if the contents of a particular WWW page

has changed, then you can of course

check/read/visit that page regularly.

But is there a simpler way to track changes?

144

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

»by using one of the available, suitable, programs loaded on your client workstation

»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

• Few systems are free of charge.

145

Current awareness services focusing on WWW pages: Tracerlock

• http://www.tracerlock.com/can use one of several external Internet indexes with a simple search query given by you, to discover relevant changed or new WWW pages for you in the future

Example

http://www.tracerlock.com/

146


Track the changes of a WWW page, by using a service free of charge

on the WWW.

Track the changes of a WWW page, by using a service free of charge

on the WWW.

147



Public access book databases

148

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 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.

149

Public access book databases: an overview

Public access book databases: an overview

• (Databases by publishers.)

• Databases by book distributors / bookshops!

• Online public access library catalogues

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

150

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.

151

Book databases accessible free of charge: examples (Part 1)


• Amazon.com (US):http://www.amazon.com/ http://www.amazon.co.uk/ note: amazon, NOT amazone

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

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

Examples

http://www.amazon.com/

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

http://www.bn.com/

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

152



• 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.buchhandel.de/

http://www.chapitre.com/

http://www.boeknet.nl/

153

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/

154

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/A part is available free of charge.

Examples

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



155

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

156

!? Question !? Task !? Problem !?!? Question !? Task !? Problem !?

Search for titles of bookswhich are relevant for you,

using an online database provided by a book publisher or bookshop.


using an online database provided by a book publisher or bookshop.

157

Current awareness service for books

• Some systems can alert the user that a new book has been published when this fits the interest profile of the user.

• Such an interest profile can be stored on the server of the system in the form of

»keywords, or

»subject categories / subject fields

• Example: http://www.amazon.com

http://www.amazon.com/

158

Public access book databases: evaluation criteria (Part 1)Public access book databases: evaluation criteria (Part 1)


• Wide coverage? Also for books in your preferred language?

• Specialized coverage for particular subjects?

• Up to date? Frequent updates?

• Abstracts, summaries, descriptions, tables of contents included?

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

159


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

»the title

»the date of publication

»the author

»the publisher

»the language

160


• Does the database producer improve retrieval by

»adding subject terms, or

»by classifying the books in categories

• Powerful search options:

» truncation? stemming?

»Boolean search combinations? proximity searching,…?

»spelling check of your search terms?

» translation of your search terms in several other languages?

161



• Is a user interface offered in your own language?

• Relevance ranking of results?

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

• Can results be limited to a certain time period?

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

162


• Good presentation of each result?

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


163


• 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

»a subject directory for browsing, besides the database with index for searching



164



Library Online Public Access Catalogues

= OPACs

165

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.

166

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

167


Which protocols are used by managers of catalogue systems

to provide access to OPACs through the Internet?

Which protocols are used by managers of catalogue systems

to provide access to OPACs through the Internet?

168

Online Public Access Catalogues: Internet protocols used for accessOnline Public Access Catalogues: Internet protocols used for access

• telnet

• (WAIS)

• Z39.50

• WWW / http / html

• WWW / http / html + Z39.50 !

169

Online Public Access Catalogues:directories

Online Public Access Catalogues:directories

The most up-to-date directories and pointers to online access library catalogues are offered online by many WWW servers.

170

Online access library catalogues:The British Library

Online access library catalogues:The British Library

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

• Access free of charge

Example

http://blpc.bl.uk/

171

Online access library catalogues:The British Library: screenshotOnline access library catalogues:The British Library: screenshot

Example

172



in the British Library.


in the British Library.

173

Online access library catalogues:The Library of Congress, U.S.A.Online access library catalogues:The Library of Congress, U.S.A.

• >15 million books + >10 million other documents

• In Washington DC, U.S.A.

• Accessible online via WWW

• Access free of charge

Example

174



in the Library of Congress catalogue.


in the Library of Congress catalogue.

175



Fee-based online public access information services

176


• 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.

• 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.

• The first commercial computer systems that make information available online were born around 1975.

• Most of them are now also available through the Internet.

177

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

178



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 Science, JCR,…)LexisNexisMSN (Microsoft)ProdigySilver PlatterSTN Swets (e-journals)...

Examples

179

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

• ...

180

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/

181

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

182

Database producers and database hosts / distributors

Database producers and database hosts / distributors

• Some database producers distribute directly their own information from their own servers, and do not (only) rely on external host servers.

• Examples:

»Cambridge Scientific Abstracts

»ElsevierCompanies / OrganizationsCompanies / Organizations

Database producers

Hosts = Database vendors

183

Database hosts / distributors:evaluation criteria (Part 1)Database hosts / distributors:evaluation criteria (Part 1)

• Contract required?

• A priori payment required?

• 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?

184


• Price of access? Price of information?

• Powerful search options: truncation, Boolean combinations, proximity searching,…?

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

• Speed of retrieval?

• Relevance ranking of results?

• Fast response? Accuracy of data communication?

• Clear output format?

185


• Online indication of costs?


• Practice free of charge?

• Good manuals, documentation and online help?

• Training courses available? Quality?


• Gateway service offered?

• ...

186

Online use of external databanks: fixed cost factors

Online use of external databanks: fixed cost factors

• Personnel !

• Equipment and maintenance of equipment

• Contract with public data communication service

• Contracts with hosts

• Manuals about external databanks

• Directories of databases

• Training of personnel

• Journals about online information retrieval

• ...

187

Online use of external databanks: variable cost factors

Online use of external databanks: variable cost factors

• Data communication

• Access to host / databank

»(time spent online)

»actions performed!

• Royalties for acquired information

• Storage of output / results

»(Printing hard copies by the host)

»Printing and/or storing on disk

• ...

188

Searching indexes of more thanone database simultaneously

Searching indexes of more thanone database simultaneously

Application/purpose:Find most appropriate database, easily, fast and cheap

189

Online access versus CD-ROM databases: factors to compare (Part 1)


• User interface

• Availability of the required data on the medium?

• Time available for access?

• Hard- and software required for access

• Maintenance of the required hard- and software

• Dependence of data communication system for online access

• How many databases available on the same system?

190



• Searching in more than one database at the same time?

• Is the complete database accessible in one search?

• Flat fee for most CD-ROMs versus pay for what you get with many online databases

• Update frequency of database(s)

• ...

191

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)

»...

192

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

193


Identify databases which may be relevant for you,

using a directory of online databases.

Identify databases which may be relevant for you,

using a directory of online databases.

194


When ASFA is available to you, develop a suitable search query

and apply this to find documents about monitoring sea water pollution.

Some advice: find and apply the relevant controlled terms (descriptors)

from the thesaurus used by ASFA.


and apply this to find documents about monitoring sea water pollution.

Some advice: find and apply the relevant controlled terms (descriptors)

from the thesaurus used by ASFA.

Example

195



and apply this to find documents that describe the state of the art in

fishing by using poison in the lakes of Tanzania. Some advice:

find and apply the relevant controlled terms (descriptors) from the thesaurus used by ASFA.


and apply this to find documents that describe the state of the art in

fishing by using poison in the lakes of Tanzania. Some advice:

find and apply the relevant controlled terms (descriptors) from the thesaurus used by ASFA.

Example

196



Online access databases about journal articles

197

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.

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

198

Online access databases about journal articles: Northern Light

Online access databases about journal articles: Northern Light

• Northern Light allows searching for the full text of articles from many journals/magazines.

• Searching is free of charge.

• Available from

»http://www.northernlight.com/

»http://www.nlsearch.com/

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

Example

http://www.northernlight.com/

http://www.nlsearch.com/

199

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.


Example

200




• Ingenta has acquired Uncover in 2000.

• Available from

»http://www.ingenta.co.uk/

»http://www.ingenta.com/

Example

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



http://www.ingenta.com/

http://www.ingenta.com/

201

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 or Conferences, doctoral dissertations) at the Institut de l'Information Scientifique et Technique, France.


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


Example

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

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

202

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.

• Current awareness services are also offered free of charge.

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

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

Example

http://www3.infotrieve.com/

203


Search for titles of journal articleswhich are relevant for you,

in a database provided free of charge.

Search for titles of journal articleswhich are relevant for you,

in a database provided free of charge.

204



Online information sources about journal titles

205

Online information sources about journal titles: introduction

Besides directories / catalogs / overviews /databases / lists of electronic, computer-based, online accessible newsletters, newspapers, journals,and besides databases about published articles in journals (bibliographic databases), information is also available through the WWW about journal titles in general: their exact names, name changes, editors, prices, formats (printed or electronic online), full text availability online, …

206Example

Online information sources about journal titles: example

Available free of charge:

http://www.publist.com/

http://www.publist.com/

207



Electronic newsletters and journals

208

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

209

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

210

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 = long delay for the electronic version

»purely electronic publications

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

211

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.

212


Which pricing schemes for access to electronic journals

do you know?

Which pricing schemes for access to electronic journals

do you know?

213

Electronic newsletters and journals: pricing (Part 1)

• Several categories (pricing models) can be distinguished:

»Free access for all

»Access without extra costs besides the price for the print version;coupled with the printed version

214


»Access with an extra cost on top of the price for the print version (for instance at 110%, or dependent on the number of potential users); coupled with the printed version

»Access not free of charge, but access to the electronic version only, at a lower price than the price of the printed version (for instance at 80%, or dependent on the number of potential users); not coupled to the printed version

215


»Access not free of charge; a printed version does not exist

»One price for access to many or all of the electronic journals of an editor = “package deal”

»Access not free of charge and the journal is one component of a bigger full-text database

»Pay per view: payment for each article that is viewed

»Payment for a license in the framework of a consortium of organisations (possible advantages of this approach: bundling of expertise, lower prices,…)

216


»Access not free of charge; a group of authorised users selects a fixed number of articles from a collection of many journals and can then access these articles without further limit

217

Electronic newsletters and journals: authentication

• To control access to fee based electronic journals some method for authentication and authorization is used by publishers or distributors:

»On the basis of the range of IP-addresses of the computer workstations used by the organisation

»On the basis of a username and password couple

—that are constant, permanent

—or that are changed often by the information provider

»Or based on a combination of those methods

218

Electronic newsletters and journals: authentication problems

• Up to now, the authentication methods are far from perfect:

»Authentication by IP-address gives problems with users on “external”, “unknown” workstations outside the simple IP-address range

»Authentication by passwords is complicated and passwords cannot be kept secret.

219

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? For ever?)

220

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)

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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, such as SFX / OpenURL (commercialised by Ex Libris)

COMPLEXITY

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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?

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Find out how you can efficiently access electronic journals

from your institute.

Find out how you can efficiently access electronic journals

from your institute.

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Electronic newsletters and journals: usage statistics

• Statistical data related to usage: the collection, standardization and exploitation should be developed further.

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How to find out if the full text of a published printed article

is also available online?

How to find out if the full text of a published printed article

is also available online?

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Directories of online access electronic archives of printed journals

Directories of online access electronic archives of printed journals

Several directories / catalogs / overviews are available of electronic, computer-based, online accessible archives of printed sources (newsletters, newspapers, journals,...):

»Fulltext Sources Online (printed)taken over in 1998 by the publisher Information Today

»Net.Journal Directory (printed)

»...

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Directories of online access electronic journals

Several directories / catalogs / overviews / databases / lists are available of electronic, computer-based, online accessible newsletters, newspapers, journals,...:

»http://www.coalliance.org/ejournal

»Scholarly journals distributed via the World Wide Webhttp://info.lib.uh.edu/wj/

»Newjour: Electronic journals and newslettershttp://gort.ucsd.edu/newjour/index.html

http://www.coalliance.org/ejournal

http://info.lib.uh.edu/wj/

http://gort.ucsd.edu/newjour/index.html

http://gort.ucsd.edu/newjour/index.html

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Computer-based information sources: criteria to evaluate their quality

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Computer-based information sources: evaluation criteria (Part 1)

Besides more general criteria applicable to all information sources, for those sources that are based on computers and networks we see the following criteria:

• Easy to navigate?

»User-friendly information system?

»Easy for users to orientate themselves within the resource and to find their way around it?

»Is the resource organised into manageable chunks of information that can be browsed easily?

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» Is a contents page or index offered that describes what is contained within the site?

» Are there good navigational links within the pages (e.g. 'back', 'forward', 'home')

» Are the links clearly labeled?

» Is the navigation process supported by images?

» Is there a single downloadable file for documents that exist as a series of separate pages?

» Is there a search facility within the resource?

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• Good user support?

»Good support that is offered to users to help them answer queries and problems that arise whilst using the resource?

»Good computer-based, contextual help, documentation, training materials or tutorials?

»E-mail contact(s) and telephone number(s) available?

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• Based on appropriate technologies?

»Are technologies and standards used that will enable users to access and utilize all aspects of the resource?

»Does the resource avoid that proprietary software should be used?

»Does the resource avoid the use of proprietary extensions to HTML, which some browsers will not be able to recognize?

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»Does the format allow access to the resource for all users, even for instance sight impaired and those who can only navigate by using the keyboard?

• Information integrity / High stability of the contents / Low volatility of the contents?

»Is there adequate maintenance of the information content?

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• System integrity?

»Site integrity relates to the stability of the site over time. This usually relates to the work of the site manager or web master.

»Realise that individual sites can be moved or withdrawn at any time by those responsible for publishing information on the Internet, and that addresses, file structures, formats and interfaces can be altered without warning.

»Is the site current and up to date?

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» Is the site proven to be or expected to be durable in nature?

» Is the site adequately administered and maintained?

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Computer-based information sources: The Internet Detective

A tutorial in English about how to assess the quality of WWW-based information resources can be accessed online free of charge through the WWW: http://www.netskills.ac.uk/TonicNG/cgi/sesame?detective

http://www.netskills.ac.uk/TonicNG/cgi/sesame?detective








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Use The Internet Detective to learn more

about assessing the quality of WWW-based information.

Use The Internet Detective to learn more

about assessing the quality of WWW-based information.

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Future trends

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Online access information: future trends

• An increasing amount of information becomes available online.

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

• The quality of server and client software is growing.

A consequence is:

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

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Online access information: future trends regarding software

• From a mix of user interface + data offered both online by the server / host, to an increasing use of client-server architecture.

• Less usage of client software specific for one application, but increasing number of applications of generic, popular, widely distributed WWW client software.

• Increasing integration of various types of information sources, servers, and client software.

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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.