Videotex behavioural research : a comparative evaluation of hierarchical and keyword-directory retrieval in three kinds of search task

Abstract

The University Academic Calendar served as the experimental database in a study of videotext information retrieval behavior. Responses on a numeric keypad operated either a hierarchical or keyword-directory retrieval system. Retrieval successes, pages accessed, search time, and time per page served as indices of search performance in single-page-solution (unipartite), multi-page-solution (multipartite), and unsolvable search problems. Relationships between performance measures and several user abilities and characteristics were examined. Pretest and post-test measures of attitudes toward hypothetical videotext applications were used to gauge the effect of exposure. Undergraduate subjects completed pre-experimental tests of spatial memory and ideational fluency, and, during the experiment attempted 20 search problems. Overall, the keyword directory retrieved more relevant information than the hierarchy. Unsolvable tasks required the most effort of searchers and unipartite tasks the least. Multipartite tasks required a large number of pages and long search times but also retrieved the greatest quantity of target information. Comparisons showed, in the unipartite and multipartite tasks, that keyword searches consumed half as many pages and half as much time as the hierarchy per unit page of information. In unsolvable tasks, the hierarchy out-performed the keyword directory, taking substantially fewer pages and less time to confirm the non-existence of target information. Performance measures were found to correlate moderately with the spatial memory scores of those who used hierarchical retrieval, but with the ideational fluency scores of those who used keyword retrieval. Post-test attitude measures reflected a significant increase in favourability in the videotex application experiences by subjects. Implications of the findings and other issues raised by the results are discussed.