The purpose of this study was to explore how adult users interact and learn during a computer-based simulation given visual and verbal forms of feedback coupled with embedded elaborations of the content. A total of 52 college students interacted with a computer-based simulation of Newton's laws of motion in which they had control over the motion of a simple screen object--a ball. Two simulation conditions were studied, each differing in how the feedback of the ball's speed, direction, and position was represented: visual feedback consisted of animated graphics and verbal feedback consisted of numeric displays. In addition, half of the simulations were supplemented with elaborations of the content modeled by the simulation in order to investigate how to promote referential processing, a key component of dual coding theory. Results showed significant differences for both the use of the elaborations and simulations containing visual feedback in helping subjects gain both tacit and explicit understanding of the science principles. In addition to the quantitative analysis, a qualitative analysis was conducted with 12 additional subjects. (Contains 23 references.) (Author/AEF)