This study used a mixed-methods approach to evaluate a hybrid teaching format that incorporated an online tutoring system, ALEKS, to address students' learning needs in a graduate-level introductory statistics course. Student performance in the hybrid course with ALEKS was found to be no different from that in a course taught in a traditional face-to-face format. Survey and focus group interviews revealed that students' experience with ALEKS and learning of statistics varied systematically across performance levels. Both quantitative and qualitative data suggest that 1) class format may not be as important as students' mathematical ability and skills for their success in introductory statistical courses, and 2) a teaching approach that addresses the underlying determinants of learning behaviors would be more effective than simply delivering the material in a different format. (Contains 4 tables.)