Definition, purposes/functions, elements of IR systems

Lesson 1

Information retrieval The technique & process of searching, recovering,

& interpreting information from large amounts of stored data (MScience & Technology Dictionary)

It relates to “the organization of, processing of, and access to information of all forms and formats” (Chowdhury, 2004, p. 1)

Structured data (e.g., students database):

Data elements are related

Designed to retrieve specific facts or records, based on a common attribute of the data elements (e.g., student no.).

IR deals with unstructured data:

No clearly defined data elements

All types of documents; e.g., abstracts or full text documents such as newspapers, dictionaries, encyclopaedias, handbooks, audio, video, images etc.

To organize documents/records in a way that facilitates easy access or retrieval of relevant information by its users.

IR systems retrieve bibliographic items or exact match of texts of queries from full text databases or multimedia information.

Documents in an IRS are processed into an index (Indexing process)

A user formulates his problem/information need in a query (Query formulation)

The IR software compares/matches the query to the index (Matching process)

The user is presented with a set of retrieved documents which he judges for relevance or appropriateness in meeting his need (Feedback)

The query can be modified if the retrieved documents are irrelevant

Must be equipped for: Prompt information dissemination Information filtering (exclude unwanted information) Active switching of information (Such as switching from web

search to email access) Receiving information in a desired format Browsing Getting information in an economical way Current literature Accessing other information systems Interpersonal communication Personalized help, and must be User friendly

1. OPAC Searching library catalogues online

checking availability of library resource.

2. Online database Provide access to peer reviewed scholarly information

resources

Are subscription or fee-based services

3. Digital libraries and web information service Information is stored in digital formats

Often free and accessed via the web

4. Web search engines Free search tools for web information retrieval

Search for information from library OPACs

Access information from bibliographic or full text databases e.g. Web of Science, LISA

Access to e-books & e-journals (World public library at http://worldlibrary.net/ , Emerald at www.emeraldinsight.com)

Access information from email services and mobile phones

Search information on company or institutional intranets

Access web information via URLs, search engines, and subject gateways (provide links to more academic, reliable information).

Access information from social networking sites.

Functions of an IR system - Chowdhury, p. 6-7

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