Abstract
The aim of this chapter is to present a conceptual and practical overview of a variety of innovative student-centered face-to-face and online pedagogical approaches for the 21st century classrooms including science, technology, engineering, and mathematics (STEM) classrooms. Various alternative innovative forms of small-group learning and online teaching/learning methods have been developed and implemented worldwide to replace or supplement the traditional lecture-based instruction. Online teaching/learning, cooperative learning, collaborative learning, problem-based learning, and team-based learning are examples of such innovative reform-based collaborative student driven pedagogies that are covered. We conclude that these innovative 21st strategies make learning in both physical and online classrooms more stimulating and motivating for students, which promote better retention of the course content, minimize dropout rates, and maximize students' learning of the course content.