This three-part paper describes the development of a software program called "The Growth Curve of Microorganisms" for a tenth-grade biology class. Designed to improve students' cognitive skills, the program enables them to investigate, through computer simulations, the impact upon the growth curve of a population of three variables: temperature, nutrient concentrations, and initial cell numbers. In presenting the sequence of the developmental steps, the first section of this report examines the basic assumptions of using computer-assisted learning (CAL) in the classroom and the criteria for efficiency, the formation of a team of developers, and how the team works. The description of the program in the second section includes the rationale for using the microcomputers and its integration into learning activities in the classroom and the laboratory, the four steps covered by the computer simulations, and the procedures for a self-assessment test. The third section discusses three factors involved in the implementation process: classroom setting, the student and self-paced progress, and the role of the teacher in the classroom. Four flow charts are provided which depict the modular course, steps of the development team stage, student self-paced activities, and classroom management activities. (DJR)