This study used a posttest only non equivalent groups design involving undergraduate students in three sections of a General Chemistry course at an R-1 institution in the Midwest. Students in the control group (spring 2012) attended class 3 times a week (150 min per week) in a theater-style classroom with 350 students (Fig. 2). They listened to lectures, watched demonstrations, and responded to the instructor's questions and prompts. During the following semester (fall 2012) the experimental group was split into three sub-groups; each sub-group attended class just once a week (50 min per week) in an ALC with capacity for 117 students. They had access to optional online lectures, solved problems in small groups during class, worked with computer simulations, played a chemistry version of the game Jeopardy, and answered clicker questions. A second experimental section of the class, also in blended/flipped format, was held in spring 2013 as a replication.
Because students self-selected into the class, random assignment to experimental and control conditions was not possible. The instructor, course content and objectives, and main course assessments were held constant. The time of day and the semester varied due to scheduling needs, and the classroom and flipped pedagogy were allowed to vary to create the conditions in this quasiexperiment