The paper reports on a user evaluation of the Micro Gallery hypertext system of Western European Paintings at The National Gallery in London. A combination of data collection methods was used, including questionnaires before and after the use of the system and direct observation with talk aloud, to examine the impact of the interface features on searching behaviour. The diagnostic analysis highlights difficulties encountered with starting off, access points, navigation, orientation and the touch screen interaction. Linear and non-linear approaches to searching arc compared for first time and experienced users and arc discussed in terms of the completeness of user mental models.