Active learning has been defined as “anything that involves students in doing things and thinking about the things they are doing.” Compared with classrooms in which students are primarily (passive) listeners and instructors are primarily (active) transmitters, active learning environments are characterized by teaching strategies that engage students in pre-planned and structured activities (in and out of class). Such activities have improved learning skills, reduced the achievement gap among students with contrasting levels of preparation (academic and socio-economic backgrounds), and lowered failure rates in large enrollment, introductory, or gateway courses. A recent meta-analysis (n = 158 studies) indicated that traditional lecturing increase failure rates by 55% and student performance on tests and concept inventories increased by 0.45 standard deviation in active learning classes. These beneficial effects were proven across science, technology, engineering, and math (STEM) disciplines, course types and levels, and are usually stronger in smaller enrollment courses. Although class activities are sometimes viewed as temporary diversion strategies to maintain students’ engagement in lecture, their impact are likely to increase when designed and implemented with clearly defined objectives and expected learning outcomes. Using classroom time to deliver course content becomes increasingly obsolete. With ubiquitous educational technology, courses can be designed so as to make students accountable for engaging thoughtfully with materials before class. In flipped classrooms (and to a lesser extent in blended classrooms), in-class time privileges individual, pair, small group or large group activities that engage students in higher order of analytical thinking and confront them with diverse and alternative modes of understanding. As such, active learning creates a community of learners who begin to think more like scientists (on a quest for new discoveries). Active learning nudge students toward an understanding that knowledge is neither given nor gotten, but constructed, a greater ability to assess their own beliefs, and the realization that learning is a worthy life-long goal.