The Critterbot is a robot designed and built by the project that has become a focal point of project research, particularly with regard to the goal of relating sensori-motor data to higher-level knowledge of the world. The Critterbot is shown in Figure 1. This small mobile robot is outfitted with an unusually rich set of redundant sensors, including infrared proximity sensors, directional light sensors, binaural microphones, a three-axis accelerometer, a gyroscope, a radio-spectrum sensor, a compass, and sensors for the battery level and for the temperature, current, and velocity of the motors driving the three wheels. The Critterbot receives digital sensory data from over 50 sources every 10 milliseconds, and generates digital motor commands for the three wheels and the 12 display LEDs at the same rate. The Critterbot’s mind, the focus of project research, also has many state variables updated up to 100 times a second. To monitor what is going on in real time we have built a flexible display tool, called Zephyr, shown in Figure 2. Zephyr enables us to easily pick out any set of Critterbot signals and display them graphically at any temporal resolution. For example, the upper-right portion of Figure 2 shows the temporal evolution of 5800 weights as they are being learned by one of our algorithms.