Expandable indexes vs. sequential menus for searching hierarchies on the World Wide Web

An experiment is reported that compared expandable indexes providing full menu context with sequentialmenus providing only partial context. Menu depth was varied using hierarchies of two, three and four levels deep in an asymmetric structure of 457 root level items. Menus were presented on the World Wide Web within a browser. Participants searched for speci®c targets. Results suggest that reducing the depth of hierarchies improves performance in terms of speed and search e ciency. Surprisingly, expandable indexes resulted in poorer performance with deeper hierarchies than did sequential menus.