Our case study is a response to the need for research and reporting on specific strategies employed by software designers to produce effective multimedia instructional solutions. A systemic approach for identifying appropriate software features and conducting a formative evaluation that evaluates both the overall effectiveness of the multimedia instructional design and the effectiveness of specific features of the software is presented. The instructional software for teaching the concept of variable was designed as a research platform and tested with 90 undergraduate students at a Midwestern university. Behavior tracking and data collection instruments (pre-test, surveys, and delayed post-test) were embedded in the software. As a part of "design-engineering-develop" approach, two potential types of feedback, "single try" versus "two tries," were tested in two experimental conditions. The results of the formative evaluation demonstrated preliminary evidence of the effectiveness of the designed software with either type of feedback for both high and low prior knowledge students. An innovative instructional strategy of helping the learner mindfully process the program feedback is described.