This study provides a rationale for adopting course materials. It demonstrates the relationship between ability to read assigned materials and academic achievement, and that selection of materials creates two groups having different probabilities of success. The sample was selected from a population of all students enrolled in Principles of Economics courses at North Texas State University in the spring semester of 1986. The Nelson-Denny Reading Test was used to determine reading ability. Assigned materials were analyzed for readability. A frustration level was determined and used to divide the sample: the group of interest, those with reading abilities below the frustration level who underwent the treatment of reading materials written above their ability to comprehend; and the comparison group, those with reading abilities above the frustration level who did not undergo the treatment.