The author observed that students enrolled in first-year college biology courses often had weak study skills. This longitudinal study examined the use of open-book tests to encourage reading and to assess the improvement of college students' study skills. There was a statistically significant improvement from the initial test to the final test given for the entire sample. This study also examined students with weaker study skills, as determined by their performance on the first open-book test, and found that they benefited more from open-book tests than did the overall sample. The entire sample had an average improvement of 4.47 points over the first test, which was statistically significant. However, the students with weaker study skills had an average improvement of 23.79 points.