Definition of an Indexing System
Let us now look at some of the definitions available in the literature of Library and Information Science. One such definition states that "an indexing system is a set of prescribed procedures for organising the contents of records of knowledge or documents for the purposes of retrieval and dissemination.", Another definition reads that "an indexing system is the means whereby an indexing language can be applied to make an index." It appears that both these definitions have common roots. The only difference is that the first definition is somewhat broader in scope. It may be stated that the need for an indexing system stems out of the work of devising index headings. These index headings mainly relate to documents dealing with compound or multi subjects although, elementary one concept subjects are not excluded from the purview of an indexing system. For convenience, indexing systems could be divided into two basic groups: the pre-coordinate systems and post-coordinate systems. On the basis of experience, it may be stated that not every index necessarily exhibits all the features of either of these two types of indexing - systems, both types of indexing systems. However, this division is useful in understanding these two categories of indexing systems.