Total Class Involvement From Bill Hill, a physics and math teacher at Casey County High School in Liberty, Kentucky: "I have found that I can use the TI-83 overhead projection devise for Calculator-Based Laboratory (CBL) activities and still involve the whole class. After cooperative group assignments, I have one member of each group form a temporary demonstration group. That group performs the activity whle other members fo the regular grups record data and measurements from the overhead, etc. Once the task is complete, the demonstration group dismantles and students return to their regular goups and complete the analysis, reports, etc. This approach eliminates the problem of not having enough CBLs for every group."