We describe the initial prototypes of several Intelligent tutoring systems designed to build students' scientific Inquiry skills. These Inquiry skills are taught In the context of acquiring knowledge of principles from a mlcroworld that models a specific domain. We have Implemented microworlds for microeconomics, electricity, and light refraction. All of the systems are highly interactive; students can pose questions, conduct experiments by manipulating domain specific factors, and record results. Using protocol studies of expert and non-expert learners using these microworlds we identify important inquiry strategies. W e have represented these strategies formally, allowing the mlcroworld to detect effective and ineffective Inquiry strategies. W e conclude with a description of a partially implemented 'inquiry coach*. This coach will be incorporated into the microworlds and teach the Inquiry strategies in the context of the specific mlcroworld domain knowledge.

This paper presents results from a study that attempted to replicate unexpected findings from a previous study (Shute & Gawlick, 1995) which investigated the effects of differential practice opportunities on skill acquisition, outcome, efficiency, and retention. These same variables were examined in a new study (N= 380), and the following results were replicated: (1) Learners receiving fewer practice opportimities completed the curriculum significantly faster than the other practice conditions, but at the expense of greater errors; and (2) Despite acquisition differences, all groups performed comparably on the outcome measure. This study also examines the effects of learner control (LC) on these same parameters. We included a condition where students chose their degree of practice, per problem set. Overall, this group completed the curriculum faster, and showed the highest outcome efficiencies, relative to the other conditions. Preliminary results from the retention part of this study (n = 76) continue to show an overall LC advantage, as well as a significant condition x gender interaction. That is, the LC condition is optimal for males, while the extended practice condition is best for females. We discuss the implications of these findings in relation to the design of efficacious instruction.