Customizing multimedia with multi-trees

The navigational design comprises two components: the structure of the hypermed ia and the layout of user interfaces. The latter aspect is the focus of usability studies ( e.g., Falk & Sockel, 2005); whereas, the former is less frequently discussed in the literature and is given scent mention in lectures at universities or business schools. This article is mainly devoted to the former aspect, and: • outlines the graph theoretic foundations for structuring hypermedia, • introduces multi-trees forcustomizinghypermedia with respect to different user groups, and • provides an overview of metrics to assess the navigational efforts of the user. The approach presented herein differs from wellestablished human-computer interaction studies (e.g., Arroyo, Selker, & Wei, 2006), because it aims at quantifying the users' nav igational efforts with respect to the structure ofhypermed ia systems rather than the i nterface design. This article presents a modeling approach, and all results are derived by a deductive analysis.