TYPES OF CATALOGUE:
You have learnt the definition, objectives and functions of a library catalogue and the physical forms in which it exists, with their distinguished features. In this Unit, we will introduce you to the inner forms of a library catalogue, which have a direct relationship with its physical forms. Inner forms of a library catalogue deal with the organisation and arrangement of bibliographic data in a catalogue entry. and the systematic arrangement of the resultant entries for storage and retrieval. In this Unit, we are concerned only with the arrangement of catalogue entries in a helpful sequence and their relative advantages and limitations.
There are a number of ways of arranging catalogue entries to fall into a helpful sequence. most popular of them, adopted in libraries, are to arrange the entries in an alphabetical c or to arrange them in a classified order on the basis of a classification scheme chosen for library for classifying its documents. The alphabetical catalogue can be separated for mitt titles, names (works of or on authors), subjects or arranged in one alphabetical sequence authors, titles, subjects etc., which is referred to as a dictionary catalogue. The classified catalogue is a subject catalogue, displaying entries by the class number of documents, which gives the structural order of the classification scheme used by the library. It is usually in two parts, the first being the classified part, i.e., in the order of the class numbers of documents and the second one is an alphabetical part or index, pointing to the classified part. The alphabetico-classed catalogue is a variety which combines the principles of alphabetical arrangement and the classified structure. The choice of a particular inner form of a catalogue for a specific library depends on the type and quality of users, the document stock built up for the library, open or closed access, library services offered, etc.