We describe Posey, a computationally-enhanced hub-andstrut construction kit for learning and play. Posey employs a ball and socket connection that allows users to move the parts of an assembled model. Hubs and struts are optocoupled in the ball and socket joints using infrared LEDs and phototransistors. Wireless transmitters in the hubs send connection and geometry information to a host computer. The host computer assembles a representation of the physical model as the user creates and configures it. This representation can then be used by application programs to control models in particular domains. ACM Classification Keywords

The usability of remote controls for home entertainment systems like TV sets, set-top boxes, satellite receivers and home entertainment centers has reached overstraining complexity: about eight to ten remote controls with about sixty to eighty push-buttons each are typical for a home entertainment system setting today. To be able to harness the ever growing remote control interaction complexity, we propose physical shortcuts to express the most frequently used control commands. Embodied into an orientation aware artifact which serves as a tangible user interface, physical shortcuts are articulated as hand gestures by the user, and converted into control commands compatible with the built in infrared receivers of standard consumer electronics. Starting with an analysis of the kinematics of the human hand, the types of grip and its correlation with the size and shape of an object which the hand grasps and holds, we study different tangible interface geometries with the potential to serve as a physical shortcut interface, and thus as a complementary remote control. Besides cubical and cylindrical artifact geometries of different sizes, also hybrid shapes are investigated with respect to their affordance, i.e. the action possibilities of an artifact readily perceivable by an actor. For the final cube like tangible interface design, ATMega168 microcontroller based electronics involving a three axis acceleration sensor and a gyroscope, together with low power IEEE 802.15.4 wireless communication components have been developed. A finite state machine based software architecture is deployed for artifact based hand gesture recognition, and table driven issuing of IR remote control commands. Finally, a fully functional cube remote control, the TA cube, is presented as a tangible remote control for an IPTV set-top box.

Abstract This study explores young children’s ability to construct and explain adaptive behaviors of a behaving artifact, an autonomous mobile robot with sensors. A central component of the behavior construction environment is the RoboGan software that supports children’s construction of spatiotemporal events with an a-temporal rule structure. Six kindergarten children participated in the study, three girls and three boys. Activities and interviews were conducted individually along five sessions that included increasingly complex construction tasks. It was found that all of the children succeeded in constructing most such behaviors, debugging their constructions in a relatively small number of cycles. An adult’s assistance in noticing relevant features of the problem was necessary for the more complex tasks that involved four complementary rules. The spatial scaffolding afforded by the RoboGan interface was well used by the children, as they consistently used partial backtracking strategies to improve their constructions, and employed modular construction strategies in the more complex tasks. The children’s explanations following their construction usually capped at one rule, or two condition-action couples, one rule short of their final constructions. With respect to tasks that involved describing a demonstrated