1. Concept of a document
Lesson 3

2. Definition and examples
In IR, a document is “a stored data record in any form” (Korfhage, 1997, p. 17.
The basic underlying concept is that the document must be stored in a retrievable form

3. Examples of documents Books Letters Messages
Parts of a book, such as an encyclopaedia dealing with different topics, i.e.,
A chapter
A section
A paragraph
Graphics
Sound/voice recordings
Images
Computer programs
Data files
messages etc.

4. Document surrogates
They are “limited representations of full documents” (Korfhage, 1997, p. 21).
Types
Document Identifier – a number/code e.g. accession or a classification number for the purpose of inventory control or document location.
Does not answer a query or satisfy an information need

5. Types
Bibliographic data/record – all the data elements used to identify, describe, or retrieve a document/publication of information content OR
A collection of data elements organized in a logical way to represent a bibliographic item or document, publication or any record of human communication.
Examples - author, title, publication date, publisher, ISBN etc. These are useful to the information seeker. For e.g., date shows the timeliness and appropriateness of the document.

6. Types
Keyword – one or a set of individual words chosen by the author/editor or sometimes dictated by the database to represent the contents of the document.
Abstract – a brief one or two paragraph description of the contents of a paper often written by the author.
Its purpose is to help a reader to determine whether the entire document should be retrieved.

7. Types
Extract – “Artificially constructed surrogates created by someone other than the author of a paper” (Korfhage, 1997, p. 23).
May comprise the first sentence of each paragraph or significant words and phrases in the document.
Review – a critical article on a book, play, recital etc., written by someone other than the author
Its purpose is to indicate the value of the document with respect to other works in the same field.
It can be retrieved separately to suit the purposes of a reader.