This doctoral thesis analyzes the effect of mastery and nonmastery teaching procedures upon student achievement and attitudes in an introductory college-geography course. Mastery learning is the teaching strategy where each segment of materials must be mastered before instruction can begin on the next segment. A classroom lecture-discussion method was used to teach randomly selected students in a control class and a mastery-oriented class. Students in the mastery group were given the opportunity to attend tutorial sessions to be retaught the material that had not been answered correctly on formative tests. Findings indicate that there were no statistically significant differences between the control class and the mastery students in either achievement or attitude. However, the author believes that the tutorial sessions were more useful for low aptitude students. (Author/DE)