Tools for incremental development of educational software interfaces

In this paper we describe the evolution of an educational software tool designed to let non-programmers build content-rich learning environments. Version 1 was a wholly model-driven authoring environment, but was unpopular with authors as they were forced them to build up-front domain representations before prototyping their interfaces. Version 2 uses a GUI method of interface development while the model is developed incrementally and as needed. In this version, authors built less of a model overall, but were more satisfied with the results. This paper discusses the natures of the two approaches to model-building and how they are authored.