This study presents a formative evaluation of "The Intelligent Physics Tutor," an interactive software program designed to improve high school physics students' problem-solving skills. The purposes of this evaluation were to describe how the "Tutor" was used in the pilot high school class; to determine teacher and student reactions to the program in terms of weaknesses, strengths, and suggestions for improvement; and to examine possible impacts of the "Tutor" on problem-solving strategy and performance. The test group comprised of three honors physics classes taught by the same teacher; only one of the three classes used the "Tutor." Multiple data sources used in the evaluation included teacher experiences and attitudes and student attitudes, achievement, and problem-solving strategies. These data were obtained via surveys, interviews, and teacher observation. Findings from the semester-long tryout indicated that both the teacher and the students were positive about the "Tutor's" instructional benefits. The most favorable reactions were given by lower-ability students who had trouble solving problems on their own. While there were no differences in achievement between the "Tutor" class and two control classes, the "Tutor" students demonstrated relatively greater use of systematic problem-solving strategies over time. (Contains 5 references.) (JLB)