Information Retrieval Transfer Cycle Dania Bilal IS 530 Fall 2007

Information Retrieval System A set of components that interact to provide feedback Comprised of interlinked entities  Agency that creates the databases  People  Documents

Interlinked Entities Agency Documents People

IR Information Transfer Inputs Processes Objectives of the System Outputs

The IR Cycle Documents are analyzed, translated, indexed, and stored. Documents are organized  Cataloging (description/representation of docs.)  Subject indexing

The IR Cycle Subject indexing a) 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 Entities may become access points

The IR Cycle Documents are stored after indexing Document representation is entered into the matching mechanism A file of document surrogates is established File becomes available for searching using a variety of entities/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

The IR Cycle Output  A set of records found and deemed relevant to a user query User judgment of retrieval

User Judgment Relevance to information need Relevance ranking by IR system Relevance vs. pertinence

Document-Based IRs Input, output, and matching mechanisms Selection of documents (done by indexers) Analysis of documents (done by indexers) Document organization and representation (done by indexers)

Document-Based IRs Analysis of user query (done by system) Match of user query with relevant documents Delivery of documents (output)

The IR Cycle

Information Seeking Process of finding information to fill a knowledge gap User requests  Known item searches  Unknown item searches  Subject searches

Discussion How does the IR transfer cycle in databases varies from the cycle in Web search engines?

Search Logic Overview Boolean logic Search parameters  Phrase  Proximity  Use of specific fields to search  Nesting