From Seo Wiki - Search Engine Optimization and Programming Languages
rule based visual programming
|Designed by||Alexander Repenning|
|Stable release||2.6.3 (February 2, 2008)|
|Influenced by||Lisp, Logo, Smalltalk|
|OS||OS X, Windows|
AgentSheets is an educational Cyberlearning  tool to create Web-based simulation games. AgentSheets is used worldwide to teach students programming and related information technology skills through game design. The built-in drag-and-drop language is accessible enough that students without programming background can make their own simple Frogger-like game, and publish it on the Web, in their first session. At the same time, AgentSheets is powerful enough to make sophisticated The Sims-like games with artificial intelligence. To transition from visual programming to more traditional programming students can render their games into Java source code.
AgentSheets is supported by a middle and high school curriculum called Scalabable Game Design aligned with the ISTE National Educational Technology Standards (NETS). Through this curriculum students build increasingly sophisticated games and, as part of this process, learn about computational concepts at the level of computational thinking that are relevant to game design as well as to computational science. The curriculum is made available through the Scalable Game Design Wiki . Research investigating motivational aspects of computer science education in public schools is currently exploring the introduction of game design in representative regions of the USA including technology hubs, inner city, rural and remote/tribal areas. Previous research has already found that game design with AgentSheets is universally accessible across gender as well as ethnicity and is not limited to students interested in playing video games .
Similar to a spreadsheet, an agentsheet is a computational grid. Unlike spreadsheets, this grid does not just contain numbers and strings but so called agents. These agents are represented by pictures, can be animated, make sounds, react to mouse/keyboard interactions, can read web pages, can speak and even recognize speech commands (Mac). This grid is well suited to build computational science applications modeling complex scientific phenomena with up to tens of thousands of agents. The grid is useful to build agent-based simulations including cellular automata or diffusion-based models. These models are used in a wide variety of applications. How does a mudslide work? When does a bridge collapse? How fragile are ecosystems? This ability to support game as well as computational science applications with the inclusion of scientific visualizations makes AgentSheets a unique computational thinking tool that is used computer science and STEM education.
This work including research, development and commercialization is supported by the National Science Foundation. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.
How AgentSheets is used
AgentSheets is used in a number of contexts worldwide:
- Middle school students create food web simulations to explore the complexity of ecological systems
- Middle school computer clubs students build computer games ranging from simple arcade classic such as Frogger to sophisticated AI-based games such as The Sims.
- High school students use AgentSheets as story telling and simulation tool of historical events such as the César Chávez grape boycott
- High school students simulate predator prey worlds and analyzed data created with spreadsheets and plots
- After school science programs show students how to build their own science simulations ranging from forest fire simulations to the spreading of viruses.
- High school students use AgentSheets as introduction to programming tool 
- Graduate and undergraduate courses on educational game design use AgentSheets to prototype, playtest, refine, and publish simple educational games 
- Research exploring Artificial intelligence and collaborative agents, e.g., Antiobjects
The original goal of this research was to explore new models of computational thinking. The first prototype of AgentSheets ran in 1989 at the University of Colorado, NCAR, Connection Machine 2. The Connection Machine is a highly parallel computer with up to 64,000 CPUs. Realizing how hard it was to program the Connection Machine the insight that "CPU cycles will always be ultimately cheaper than cognitive cycles" led to the exploration of several new programming paradigms:
- Agent-Based Graphical Rewrite Rules: (1991) Behavior such as a train following train tracks can be specified through before/after rules. These rules can be created by programming by example. The user would tell the system to watch the train; the user would move the train on train track one step and stop recording; the system would create the rule allowing trains to follow train tracks. Agent-Based Graphical Rewrite Rules were later also used in the KidSim/Cocoa/Creator kid programming tool.
- Semantical Rewrite Rules: (1994) It became clear that Agent-Based Graphical Rewrite Rules used in AgentSheets91 and KidSim/Cocoa/Creator were not powerful enough for a number of applications that required more general pattern. For instance, it was simple to create a rule to make a train follow a straight segment of train track but the number of rules quickly exploded when trying to have trains follow all combinations of turns and intersections. Semantic rewrite rules could interpret rules topologically. With a single rule a user could create a complete train that follows train track behavior.
- Programming by Analogous Examples: (1995) New behavior can be created through analogies. For instance the behavior of a car can be described as analogy to trains. A car moves on a road like a train on a train track. A challenge to this approach is conceptual exception handling. Analogies are often either incomplete or too general. This requires that users can refine programs produced by Programming by Analogous Examples.
- Tactile Programming: (1996) Drag and drop interfaces can be used to compose syntactically correct programs. In Visual AgenTalk (VAT), a rule-based visual programming language, users create rules by dragging and dropping conditions and actions from palettes. The tactile aspect of Visual AgenTalk allows users to perceive through drag and drop what programs do. By dragging and dropping conditions, actions, rules and even methods onto agents they see the consequence of invoking program fragment without having to write a test program. Similar drag and drop programming can later be found in the Etoys language (part of Squeak), in Alice and in Scratch.
- AgentSheets Inc.: (1996) With the support of the National Science Foundation AgentSheets has become a commercial product. The programming model has been extended, more interaction modalities have been added (e.g., speech recognition (Mac)), scientific visualization has been refined (e.g., 3D real time plotting (Mac)), and AgentSheets has been localized (e.g., Japanese and Greek).
- Scalable Game Design: (2008) A game design based free curriculum covering computational thinking ideas from elementary to graduate school based on AgentSheets. The mission of Scalable Game Design is to bring computer science education to public schools through game design.
- Web based simulation (WBS)
- ↑ Cyberlearning defined by the National Science Foundation
- ↑ Scalable Game Design Wiki
- ↑ publications related to the Scalable Game Design project
- ↑ grape boycott project with simulation
- ↑ An example GK-12 NSF program using AgentSheets: the Memphis Tri-P-LETS project
- ↑ sample games called gamelets