The main thrust of this study, therefore, revolved around the "scale-up" of the Case Instructional Sequence into a classroom size application able to be implemented by instructors with little additional practice in employing thistype of instructional sequence. Specifically, the purpose of this study was to determine the effect of the Case type treatment on the performance of two successive ninth grade physical science classes at a private, college-preparatory, secondary school in northeast Florida. These groups were to be assessed using the Tobin and Capie Test of Logical Thinking, a measure which could help assess their respective Piagetian stage.