Over the past decade, several reports have recommended a shift in undergraduate biology laboratory courses from traditionally structured, often described as "cookbook," to authentic research-based experiences. This study compares a cookbook-type laboratory course to a research-based undergraduate biology laboratory course at a Research 1 institution. The research-based lab course had several hallmarks of authentic research: a single longitudinal research focus, research questions with currently unknown answers, student-determined experimental designs, and collaboration among lab peers. Twenty students in the research-based lab were matched with 20 students in the cookbook lab on the basis of five demographic characteristics. This study found that students in the research-based lab had more positive attitudes toward authentic research, higher self-confidence in lab-related tasks, and increased interest in pursuing future research compared with students in the cookbook laboratory course. This study provides empirical evidence supporting the recommendations for incorporating more authentic research components in laboratory courses. (Contains 2 figures and 7 tables.)