This study examined the effects of cooperative testing versus traditional or individual testing and the impacts on academic achievement, motivation toward science, and study time for 9th grade biology students. Research questions centered on weekly quizzes given in a flipped classroom format for a period of 13 weeks. The study used a mixed methods research design, which combined quantitative and qualitative data collection techniques. The study examined 66 students enrolled in three sections of a 9th grade biology course at a private K-12 school. Students were randomly assigned to groups of three or four students. Weekly quizzes on regularly assigned curriculum material were provided from the flipped classroom videos. Six quizzes were randomly selected for each class to be in the cooperative testing format and six quizzes were randomly selected to be given individually or traditional-style testing format. Week 7 was reserved for administration of the mid-study questionnaire and no quiz was administered. Quantitative data collected included student grades on the 12 weekly quizzes. Qualitative data were also collected from pre-study, mid-study, and post-study questionnaires as well as semi-structured individual interviews and one focus group. Cooperative testing groups scored higher on the quizzes than when students took quizzes as individuals for five of the nine quizzes analyzed. Students did not score significantly higher than the best scorer in groups taking quizzes individually. For one quiz, the best scorer did better than the cooperative groups. Overall, cooperatively tested groups in some cases scored higher than the average of groups taking the quizzes individually, but the impact was not consistent across all quiz weeks. Difficulty level of the material, contextual factors, and ceiling effects are among potential explanations of the inconsistent outcomes. Across the study, motivation toward science stayed the same or increased depending on the aspect of motivation examined. Student attitudes of cooperative testing, group functioning, and overall satisfaction were positive throughout the study. The student responses indicated they found the experience in cooperative testing beneficial to their own learning process and relevant for future career success. Study time was consistent throughout the study and corresponded to the length of the video lesson each week. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]