Visual AgenTalk®

Visual AgenTalk tool is a rule-based end user programming language for Agentsheets. It employs a new approach to end user programming called Tactile Programming. Tactile Programming primitives and programs not only have enhanced visual representations to help program readability, but also have interactive interfaces to assist with program writability. Tactile Programming eases program composition, comprehension and sharing.

• Composition: Programs can be decomposed and composed incrementally along clearly defined boundaries.
• Comprehension: Perception by manipulation allows end-users to efficiently examine functionality. Any language component at any time can be dragged and dropped onto any agent. The component will execute with visual feedback revealing conditions that are true or false and showing the consequences of executed actions.
• Sharing: Tactile programming supports a migration from solitary to social programming. Entire simulations, individual agents, rules and new language primitives can be shared via the World Wide Web by simply dragging them from the web page into the AgentSheets environment. No plug-ins required.

Tactile Programming

The AgentSheets environment has a history reaching back to 1989. We have a created over 100 projects with AgentSheets system in the past. Some of them as one afternoon hacks, others as multiple person-year projects. In this process we have experimented with extensions to object-oriented programming frame works, programming by example and with graphical rewrite rules. At the same time we realized the power of end-user programming with graphical rewrite rules but also their limitations.

The Visual AgenTalk tool is a recent (started in 1995) effort with which we explore new scaleable programming paradigms that would feature the same ease of use for end-user programming but allowing users to gradually move towards the power of some of the more traditional programming paradigms. The Visual AgenTalk tool is an instance of what we call Tactile Programming extending visual with tactile perception. This is trivializing complex research issues, but in essence Visual Programming is employing visual perception to simplify programming by increasing the readability of programs. Tactile Programming does not question this goal but hopes to make programming more accessible to end-users by adding the perception of manipulation to visual perception. In Tactile Programming programs are no longer static representations nor is the notion of manipulation reserved to only edit programs. Instead, tactile program and their representations are dynamic including manipulation. In result, Tactile Programming turns into a unified program manipulation paradigm, that is a way to conceptualize programs, that supports the composition, comprehension and even sharing of programs through the World Wide Web. Tactile Programming is its very early infancy. The Visual AgenTalk tool in its current form is a fresh seed of an evolving programming paradigm.

All this is fairly abstract especially because the benefits of tactile perception are hard to explain well in a static medium such as this document printed on paper.