Using statecharts to model hypertext

This paper describes how to use statecharts to model hypertext. Statechart is a formal graphical model based on state transition diagram and hypergraph. The statechart model is compared with other models for hypertext based on simple node-and-link graph, first-order logic formulae, hypergraph, and petri net. The features of statecharts relevant to the modeling of hypertext are described. Statecharts for the common features in frame-based and scrolling-based hypertext are given. Then statecharts are used to model the various buttons supported in a real-life production hypertext system, Guide (both the Unix version and the version marketed by Owl International Inc.). These examples illustrate that statecharts can be used to abstract the structure from the content of hypertext, and to model the structure and the browsing semantics of hypertext clearly and vividly.