CRANV2 Test Environment chapter Cyril Cleverdon Michael Keen Cranfield An investigation supported by a grant to Aslib by the National Science Foundation. Use, reproduction, or publication, in whole or in part, is permitted for any purpose of the United States Government. - 13 - are similar groupings for the other terms. For Index Language 1.5, Quasi-synonyms, the term Sonic is combined with Acoustic' and Reaction now forms a group which includes the quasi-synonyms Energy, Force, Action, Behaviour, Kinetic, Response. With Index Language 1.7, 1.8 and 1.9, the groups for each starting term are determined by the decisions taken in the compilation of the single term hierarchies as given in Appendix 5.3 of Volume I. There is nothing to add regarding the search prescription, for it was the search rules that were capable of variation; this could be achieved by varying the coordination level or by selecting acceptable combinations of the search terms. As has been noted, all possible levels of coordination {logical product) were investigated at every stage, and therefore the effect of any rules that might be postulated concerning a minimum coordination level that would be acceptable can be seen from the tables of results. For instance, if a question had six terms, then the results would have been recorded for a search made with all six terms, then for a search with five terms, then with four terms and so on down to a single term search. No test was made in which the searches of a set of questions either commenced or were terminated by a subjective decision that varied from question to question. The main variations introduced as search rules concerned the combinations of terms that were accepted. The six variations tested are given in Fig. 2.9. TYPE A Any combination of terms accepted , I I TYPE B TYPE C TYPE E Single terms grouped into concepts, and sub- ordinated terms not accepted without their basic terms. selection of terms made from original question, any combin- ation of the selected terms accepted. t TYPE D Sets of specified combinat ions demanded at each coordination level TYPE F Specified combinations of the selected terms demanded. Matching demand in terms of language 1. . i ii!~! i'!i FIGURE 2.9 SUMMARY OF SEARCH RULES