Abstract
Earlier research has shown that human judgements, particularly retrospective as distinct from real‐time evaluations of painful experiences, are fundamentally flawed when superseded by other experiences. Describes a methodology for the evaluation of user experiences, assisted by a user‐centered co‐design tool for planning, creating and conducting wide‐ranging usability data acquisition throughout the system life cycle from inception to replacement. The results from the tests in this study were found to support the findings from recent cognitive psychology research on J/DM‐PPR theoretic biasing effects. The importance of the findings for software systems, and for interactive Web site development, is that if the interactive features which tax the user's patience and cognitive capability are not severely restraining, then users will be left with a better impression of the usability of the system than would be the case otherwise.