Since the 1970s, interactive engagement methods have been introduced in science classes , including, but not limited to: cooperative learning , peer instruction and student team-achievement division (STAD) method ; educational computer game-based learning ; e-learning ; and web-based learning, some of which relies on gaming . Common to all of these methods is the introduction of an in-class activity that keeps students engaged in the learning (and, sometimes, evaluation) process, in contrast with traditional approaches of students' passive presence while instructors deliver content.