Components of an IRS
Lancaster [1979] considers that an Information Retrieval System (IRS) comprises the following components:
i) the document selection sub-system
ii) the indexing sub-system
iii) the vocabulary sub-system
iv) the searching sub-system
v) the sub-system of interaction between the user and the system (i.e., user interface)
vi) the matching sub-system, that is, the system that matches the document representations against the user requirements.
All the above mentioned sub-systems are utilised in the performance of the following activities:
- information resource building,
- database creation and maintenance, and
- Information retrieval and dissemination.