Chimera, RichardShneiderman, BenThree different interfaces were used to browse a large (1296 items) table of contents. A fully expanded stable interface, expand/contract interface, and multi-pane interface were studied in a between-groups experiment with 41 novice participants. Nine timed fact retrieval tasks were performed, each task is analyzed and discussed separately. We found that both the expand/contract and multi-pane interfaces produced significantly faster times than the stable interface for many tasks using this large hierarchy; other advantages of the expand/contract and multi-pane interfaces over the stable interface are discussed. The animation characteristics of the expand/contract interface appear to play a major role. Refinements to the multi-pane and expand/contract interfaces are suggested. A predictive model for measuring navigation effort of each interface is presented. (Also cross-referenced as CAR-TR-539)en-USTechnical Report