New indices for bibliographic data and their applications

The KWIC Index is a widely-used tool for finding desired paper titles since it is simple yet very powerful. So in a bibliography of some specific area, the KWIC Index of Titles, Author Index and Subject Index are normally used. These indices are, however, not always sufficient for finding mutually-related papers. In this paper new indices for bibliographic data will be presented together with their applications. The RS Index (Reference Structure Index) handles reference citation structure and is suitable for detecting influential papers, getting research trends and finding mutuallyrelated research fields. A basic algorithm and improved algorithms have been developed, each of which requires memory only proportional to the number of papers to be handled (i.e. minimum). Functions of these algorithms are explained and example outputs are shown (see Figures 1,2,9 and 10). The MULTI-KWIC has a capability of automatic detection of key phrases by finding maximum common subsequences contained in the paper titles. Using these key phrases, the following two kinds of indices are generated: (1) A MULTI-KWIC list (a linear list of titles ordered by one key phrase and one keyword, as in Figure 6), and (2) a yeardistribution table (for each key phrase a table which shows identifications of papers classified by year is prepared, as in Figure 8). These new indices are applied to 1600 papers in relational database and related areas which have been collected by the authors. The result shows their usefulness in bibliographic data-handling. A personal information system based on these indices has been also developed.