Of the major models, the Web of System Performance (WOSP) model provides the most comprehensive basis for information system evaluation. The research question was how well the eight WOSP performance criteria: functionality; usability; flexibility; reliability; security; extendibility; connectivity; and privacy, applied in evaluating information systems. For this, it was important to show that these concepts can be established and identified clearly and with a valid meaning that users would consider important; that users prefer the eight WOSP criteria to the current dominant instrument for evaluating software; and that they rate at least three of the WOSP criteria as being important for evaluation. For this, conjoint analysis was used. A browser was selected as the experimental software for this research. The results showed that users found the WOSP model's concepts to be clear, valid and important for the evaluation of browsers. They also preferred using this model for the evaluation of browsers. Finally, while users attached different levels of importance to the various performance criteria for the selection of browsers, six of the criteria were important to a significant degree.