The interaction of result set display dimensionality and cognitive factors in information retrieval systems

A visual information retrieval environment provides visualization features that help users manage the large result sets that are typical in many information retrieval environments. In many of these visual interfaces the spatial layout of document surrogates is used to communicate information about document to query interrelationships. In these systems it is difficult to determine if the spatial layout is responsible for system effectiveness differences or if other system features are involved. In this study we examine the effectiveness of a two-dimensional display format compared to a more standard (one-dimensional) sorted result list. The Visual Information Browsing Environment (VIBE) (Olsen et al., 1993; Korfhage, 1997) was modified to produce two systems that varied only on result display dimensionality. The effectiveness of a display is determined by the degree to which the visual representation is consistent with the cognitive abilities of the users of a system. For this reason we also investigated the interaction of the verbal and spatial abilities of users, as measured by cognitive factors batteries, with the dimensionality of the result display. Subjects took two Factor-Referenced Cognitive Tests (Ekstrom, French, and Harman, 1976): Factor VZ: Visualization (Paper Folding Test-VZ-2) the Verbal Fluency (Controlled Associations, test FA-1). Subjects were broken into two groups, one for each display type. They used the systems to search for full-text documents that described species of plants that matched other descriptions of the same species. The interface effectiveness was measured by number of tasks solved, recall effort and median task completion time. Automated system monitoring provided detailed information about the search behavior of individual subjects.