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Information Options
Print Databases
CD-ROM Web-based Command-driven (e.g., Dialog)
Web-based interface Text-based interface
Print Option
Periodical indexes Most are inexpensive
Subscription Owned by library Easily accessible One user per one volume/section used Citations to magazine & journal articles Update
CD-ROM Databases
High storage (650 mg to over a gigabyte) 650 mg equivalent to 250,000 pages of
text or 1 million catalog records Can be loaded on stand-alone or
networked computers. Site license is needed
Command-Driven Databases
Search skills User information need
Search topic negotiation Up-to-date Access to >100s of databases Cost varies with database Web- and text-based interfaces
Information Retrieval System (IR)
A set of components that interact to provide feedback
Comprised of interlinked entities Agency that creates the databases People Documents
The IR Cycle
Documents are analyzed, translated, indexed, and stored.
Documents are organized Cataloging (description/representation of
docs.) Subject indexing
The IR Cycle
Subject indexinga) Determination of subject content
(conceptual analysis)b) Translation of content into language of
the system (controlled vocabulary)c) Abstracting
The IR Cycle
Language of the system (controlled vocabulary) List of subject headings (Pre-coordinate) Thesauri (Pre-coordinate) Classification scheme
The IR Cycle
Documents are represented by other entities Author(s) Date of publication Language Identifiers
The IR Cycle
Entities may become access points Documents are stored after indexing Document representation is entered
into the matching mechanism
The IR Cycle
A file of document surrogates is established
File becomes available for searching using a variety of access points
The IR Cycle
User Query Analyzed for conceptual content Translated into the language of the
system (matched against controlled vocabulary and keywords)
Matched against document surrogates in the database
Explanation of the IR Cycle
Output A set of records found and deemed
relevant to a user query User judgment of retrieval
Document-Based IRs
Input, output, and matching mechanisms
Selection of documents (done by indexers)
Analysis of documents (done by indexers)
Document-Based IRs
Document representation (done by indexers)
Analysis of user query (done by system)
Matching user query with relevant documents (done by system)
Delivery of documents (output)
Information Seeking
Process of finding information to fill a knowledge gap
User requests Known item searches Unknown item searches Subject
searches
Information Seeking Models Ellis’ Behavioral Model Kuhlthau’s Information Search Process Model Nahl’s ACS Model Marchionini’s Information Process Model Wilson’s Problem-Solving Model Belkin’s Information Seeking Strategies (ISS) Belkin’s Anomalous State of Knowledge (ASK) Dervin’s sense-making theory
Ellis’ Behavioral Model
Describes 8 information seeking patterns of social scientists, physical scientists, and engineers in using hypertext (e.g., the Web) Starting (Surveying), Chaining, Monitoring,
Browsing, Differentiating (Distinguishing), Filtering, Extracting, Verifying, Ending.
Kuhlthau’s ISP Model
Information search process from the user’s perspective in traditional environment
Affective, cognitive, and sensorimotor Six stages:
Initiation, Selection, Exploration, Formulation, Collection, Presentation
Nahl’s ACS Model
Taxonomic approach for identifying the levels of information seeking behaviors
Searcher’s feeling (A), thinking (C), and doing (S) is termed “information behavior”
Levels are sequential and continuous
Marchionini’s Model
Problem solving approach to understanding information seeking process in the electronic environment
Eight processes: Problem recognition, Problem definition,
Selection of system/source, Problem articulation (query formulation), Search execution, Examination of results, Extraction of desired information; Reflection, Iteration, and Stopping of search process
Wilson’s Problem-Solving Model
Goal-directed behavior of problem solving From uncertainty to certainty through
the problem-resolution process: Problem identification, Problem
definition, Problem resolution, Solution statement (has affective dimensions)
Stages are sequential and non-linear
Belkin’s ISS Model
Task-oriented with 4 sets of tasks: Browsing: scanning or searching a resource Learning: expanding knowledge of goal,
problem, & system used Recognition: identifying relevant items Meta information: interaction with items that
map the boundaries of the task
Dynamic process
Belkin’s ASK Theory
ASK (Anomalous State of Knowledge) “The cognitive and situational aspects that were the reason for seeking information and approaching an IR system” (Saracevic, 1996).
Knowledge gap (anomaly) and the need to solve it
Implications for system design
Dervin and Sense-making
A need to make sense of the world or a current situation
A state that arises within a person, suggesting some kind of gap that requires filling.
Gap is filled by information
Dervin’s Sense-making A search starts with questions
directed at making sense of a current situation.
Communication is central to “bridge a knowledge gap.”
Strategies used are shaped by the user’s conceptualization of both the gap and the bridge, and by answers, ideas, and resources obtained.
Dervin’s Sense-making
Affective states (emotions, feelings, attitudes, etc.) are as vital as cognition.
Anxiety and uncertainty are reduced as the gap becomes smaller.