A theoretical framework for assessing the attractiveness of websites based on Adaptive Decision Making theory is introduced. The framework was developed into a questionnaire and used to evaluate three websites which shared the same brand and topic but differed in aesthetic design. The DSchool site was favoured overall and was best for aesthetics and usability. The subjective ratings of the sites were in conflict with the subject-reported comments on usability problems. Subjects were given two scenarios for their preference. They changed their preference from the DSchool to the HCI Group’s site for the more serious (PhD study) scenario; however, design background students remained loyal to the DSchool. The implications of framing and halo effects on users’ judgement of aesthetics are discussed.