Library and Information Science

LISA machine-readable tapes have been produced since 1976 and become an important database for the information retrieval systems which provide “library and information fields” with document information. LISA tapes are the replica of the printed-versions and they also have following unique access points; 1) classification codes, made of CRG classification schedule. 2) two kinds of uncontrolled keywords sets, one is classification headings and the other is the entries to be appeared in the printed alphabetical subject index.

These access points themselves are powerful tools as search keys for machine systems, but search methods will be different between machine and manual systems. Therefore, it is not wise to use them which are devised for the printed-versions in the machine system without any modification. For example, manual searches from multiple aspects can only be done in the alphabetical subject index. Classification codes and classification headings are made only for single aspect searches.

This paper analyzes three kinds of access points from the point of recall and precision, and presents access procedure from their constituents to the access points and reasons why they are valuable.