This study explored the effectiveness of an adaptive web-based learning tutorial designed to teach three modules of a college level introductory statistics course. Specifically, the impact of the tutorial on student knowledge, motivation, and study time was examined. One hundred thirty four college students were randomly assigned to study from either an adaptive or a non-adaptive version of the tutorial. Data were obtained through surveys, achievement tests, and system logs. Results indicated that students' performance on a knowledge test was significantly higher for students in the adaptive version. Similarly, tutorial study time for students in the adaptive version was significantly higher than those in the non-adaptive version of the tutorial.