Tracking 3D puzzle pieces for collaborative learning environments

Children naturally learn about their world by manipulating objects within it. Playing with blocks and puzzles helps to develop their understanding of spatial relationships and other mathematical concepts. Using physical objects also allows them to work and learn in groups. Yet sometimes they need outside intervention from an adult or knowledgeable guide to help them learn more and stay engaged longer. Unfortunately, instructors often have too many students to give each one adequate attention. Our work focuses on developing computer-based "guides on the side" that can "watch" as children play with physical puzzles, and offer help or suggestions as needed. Our approach is to use the physical puzzle pieces as parts of a tangible interface. With our system, children are free to explore and collaborate without a computer, yet they can benefit from the computer's instruction as they need it. We have successfully implemented and tested a 2D Tangram puzzle using this approach [Scarlatos 2002]. In this sketch we present our most recent work, which extends these ideas to the third dimension and applies them to a Soma Cube puzzle. This work is unique in that we are tracking multiple wireless 3D objects, in a small space, simultaneously. Here, we present two approaches to this problem. We have also developed a novel representation for the state of the 3D puzzle, which we describe, This representation enables our system to select appropriate hints, give encouragement as progress is made, and offer congratulations when the solution is found.