This article presents a rationale for using active involvement techniques, describes large- and small-group methods based on their documented effectiveness and applicability to K-12 classrooms, and illustrates their use. These approaches include ways of engaging students in large groups (e.g., unison responses, response cards, dry-erase boards, thumbs up), small groups (e.g., Numbered Heads Together, jigsaw, reciprocal teaching), and partner activities (e.g., Think-Pair-Share and peer-teaching). These techniques allow teachers to provide interest and variety in their instruction, simultaneously engage all students, and conduct ongoing informal assessment of students' skills.