Redundancy and Irrelevance in Two Level Hypermedia

In this article we introduce the concept of Two Level Hypermedia. We describe a conceptual model for Hypermedia, and focus especially on the concept of a view. We introduce the concept of a power index expression as a structured characterization mechanism. Next we describe a characterization calculus, starting from the characterizations of fragments. This provides us with a means of comparing Hypermedia objects. Views are then analysed on the basis of the notion of a sequence. We introduce properties such as redundancy and irrelevance with which views can be judged.