Authoring Interactive Behaviors for Multimedia
The tools for authoring multimedia presentations start with sophisticated interactive tools like Director and ToolBook. However, to make the presentations truly interactive requires programming in “scripting languages.” These languages have generally been difficult to learn for non-programmers. “Interactive behaviors” allow users to click on, move, or otherwise interact with objects on the screen, as opposed to just watching the presentation like a TV show. Behaviors range from simply clicking on buttons or links, to sophisticated interactions with computerized characters. This paper presents a variety of ways we are studying to make authoring of these interactive behaviors more accessible to non-programmers. One approach is “demonstrational” techniques, where the author gives examples of the desired actions and results, and the system generates the code to perform the same actions at run time. Using demonstrational techniques has proven successful for specifying simple behaviors. To represent the behaviors and allow the author to edit them, we are investigating new languages which are designed to be more “natural” because they are based on how non-programmers actually think about these tasks. Human-factors studies have been performed to investigate how people naturally express algorithms. These studies have revealed some general principles which can be applied to the design of new languages, such as that a general case is often expressed first, with exceptions afterwards, and that loops are avoided by applying operations to sets of objects. Using these new results, along with results from the fields of Empirical Studies of Programmers and Human-Computer Interaction, we can create languages that are easier to learn and more effective to use. This will enable a wider range of people to read, generate and modify the code.