No single pedagogical model or style is followed in all the materials in the series, as different authors have different styles. All try to use the full interactive capabilities of the computer. Nevertheless, a single approach is common in several modules.
This model is the learning cycle, developed by Robert Karplus at the University of California, Berkeley. Working from a Piagetian basis, Karplus distinguished three stages in the learning cycle. These are an initial experiential stage, when students build up intuition about the ideas; a second more formal tutorial stage, often thought of as the sole stage in learning; and a third stage in which students must act with what has been learned.
In the Educational Technology Center, including the Scientific Reasoning Series, we have extended the concept of the learning cycle to allow for internal mastery testing and additional learning sequences based on testing. We refer to this strategy as the mastery learning cycle, illustrated in Figure 1.
Figure 1. The Mastery Learning Cycle
The mastery learning cycle simulates a scientist's approach. Thus, it is appropriate in the Scientific Reasoning Series whose main objective is scientific literacy in the general population. The experiential stage corresponds to the initial gathering of evidence, the empirical investigations on which later theoretical structures can be based. The scientist may develop hypothesis, makes predictions based on the hypotheses, verifies these predications with further empirical evidence and refines the tentative theoretical conjectures. This process is similar to mastery learning.
In many units students play the role of the scientist investigating some scientific phenomenon, gathering evidence to use in testing hypotheses developed. As with the development of science, we do not expect the user to discover immediately reasonable hypotheses. Partial hypotheses are developed that later turn out to be inadequate for the full situation. We do not, however, develop all methods possible in science. Unlike a ``pure'' discovery method, however, students are not completely on their own. Students receive selective aid appropriate to their needs. We want all students to succeed, and in a reasonable period of time.