Component-Based Authoring of Complex, Petri net-based Digital Library Infrastructure

Abstract

caT, a Petri net-based hypertext system, serves as a platform for unified modeling of digital library infrastructure and its governing policies, user characteristics, and their contextual information. Traditionally, users have created caT networks from scratch, thus limiting their use to small collections. In this paper we introduce TcAT, a component-based authoring tool, which enables the creation of large caT nets that can represent interaction-rich, real-life spaces such as libraries and museums. TcAT implements composition operations from Petri net theory, allowing authors to select and modify existing net fragments as templated building blocks for larger networks. Authors may switch between visual and textual modes at will, thus combining the strengths of expressing large nets textually and selecting net fragments via point-and-click interaction. A user evaluation of the new authoring mechanisms suggests that this is a promising tool for improving the efficiency of experienced users as well as that of novice users, who are unfamiliar with the Petri net formalism.