Cognitive Abilities and the Measurement of World Wide Web Usability

Usability of an interface is an emergent property of the system and the user; it does not exist independently of either one. For this reason, characteristics of the user which affect his or her performance on a task can affect the apparent usability of the interface in a usability study. We propose and investigate, using a Wikipedia information-seeking task, a model relating spatial abilities and performance measures for system usability. In the context of World Wide Web (WWW) site usability, we found that spatial visualization ability and system experience predicted system effectiveness measures, while spatial orientation ability, spatial visualization ability, and general computer experience predicted system efficiency measures. We suggest possible extensions and further tests of this model.