A major determinant of the success of educational intranet sites is their usability. In addition to measures of task performance and navigation behavior, psychometric instruments are used to evaluate usability and the quality of human-computer interaction more generally. However, there is a lack of validated instruments for the evaluation of sites. The aim of the present study was to establish the psychometric properties of scales for measuring the quality of interaction with educational intranets. In two experiments, undergraduates (n = 81 and n = 109, respectively) performed an information retrieval task using different versions of the same university intranet site. Psychometric properties of the instruments were analyzed. The quality of the scales is evaluated, recommendations for their use are given, and further research into the scales is outlined. (Contains 2 figures and 5 tables.)