“This article reports on a study which used results from 119 scenario-based evaluations of 36 museum Web sites to develop a conceptual framework for analyzing the usability flaws of museum Web sites. It identifies 15 unique dimensions, grouped into five categories, that exemplify usability problems common to many museum Web sites. Each dimension is discussed in detail, and typical examples are provided, based on actual usability flaws observed during the evaluations. The availability of this conceptual framework will help the designers of museum Web sites improve the overall usability of museum Web sites in general.” (Paul F. Marty and Michael B. Twidale – First Monday 9.9)