MONO91 Indexes Compiled by Machine chapter Mary Elizabeth Stevens National Bureau of Standards A final special case of a computer-compiled index should be noted. This is the work of Schultz and [OCRerr]erpherd with reference to the annual meetings of the Federation of American Societies for Experimental Biology (FASEB) (Schultz and3hepherd,1960 [532]; Schultz, 1963 [527];Shepherd 1963[5451". 1/ The indexing terms are generated first by the authors of the papers but are then run against a computer program, which by thesaurus-type look- up eliminates synonyms and supplies syndetic devices in addition to formatting the subject index for printout. The machine-readable thesaurus developed for this project presently performs the following four basic functions (Schultz, 1963 [527]): 1. It accepts words from titles and indicia supplied by the authors without modification if they match acceptable indexing terms. 2. It recognizes certain other words as acceptable if modified and modifies them accordingly, for example, by "use" directions for synonyms and near-synonyms. 3. It adds additional indexing terms when certain words occur, an example being penicillin', use also `antibiotics'. 4. It deletes certain words if they do not occur in the context of an acceptable indexing phrase. 2. 3 Tabledex and Other Special Purpose Indexes The uses of machine techniques in index compilation so far discussed represent instances in which conventional tools of bibliographic control can be prepared at lower cost or more rapidly, or both. In addition, however, certain new and unconventional types of index have been or are being produced with the aid of computers. The Tabledex method, as proposed by Ledley in 1958 (Ledley, 1958 [352], Zusman, et al, 1962 [661]; O'Connor, 1960 [442]),, involves coordinate indexing in bound book form, with special features to facilitate search, conserve space and display index terms co-occurring with a given term for a given item. 21 A major advantage claimed for this method is that by the use of computers bibliographies and book-form indexes can be organized, compiled, and printed in page format within a matter of hours. A Tabledex index typically consists of a bibliography proper, in which each citation has been assigned an identifying number; an alphabetical list of the indexing terms used, 1/ 2/ These investigators claim the first production of a conventional subject index by computer. See, for example, O'Connor, 1960 [446], p. 241: "Ledley approximately halves the average size of the document descriptions required by imposing an order on the vocabulary of indexing terms. When a document description belongs in a term subset, only those terms of the description need to be recorded which come later in term order than the term of the term of the subset. This illustrates another type of storage organization." 25