Okapi '84: Designing an Online Public Access Catalogue


This version of Okapi resulted from a two year research project funded by the British Library and the DTI. It involved investigating how Local Area Network technology and microcomputers might be used for library applications. The project was based at the Polytechnic of Central London, now Westminster University.

Background

In the early 1980s, computerised library catalogues tended to be technology-centred rather than user-centred, and users typically had to learn a query language or to type Boolean search expressions to retrieve the documents they wanted. One of the key aims of the Okapi '84 project was to use Okapi software to build an OPAC (an Online Public Access Catalogue) which provided support to users during searching. The aim was a system which would be easy to use by someone totally unfamiliar with online catalogues but would not be tedious for the experienced user.

Okapi '84 was designed to run on a local area network providing support for PCL's library sites.

Design

Okapi '84 allowed users to search for specific items by author and/or title as well as more general subject searching by typing natural language queries in a form-based display. All commands required only a single keystroke.

Search trees were used to analyse input and determine how the search was to be done. Using "best match" retrieval, Okapi searched indexes for strings which matched the query. If there were no close matches, users were shown the index starting at the nearest match. Search results were presented in rank order according to how well the records matched the user's query.

Evaluation

A range of methods were used to evaluate Okapi '84 including transaction logging (whereby the computer automatically records every detail of a search session), user observation, questionnaires and structured interviews. The evaluation showed that Okapi '84 was popular with users and fulfilled its proposed role of providing user access to library data across an LAN. The results also pointed to areas which could be developed such as spelling correction facilities, better help messages and a greater emphasis placed on subject searching.

Click here for Okapi '86