This document provides a list of 39 interactive techniques that can be used in classroom lectures to engage students and assess their understanding of course material. Some of the techniques include having students analyze images, discuss questions in think-pair-share activities, fill in outlines, participate in polls and discussions, and connect course concepts to real-world examples. The techniques aim to make lectures more interactive and help students learn more effectively compared to passive listening. Not all techniques will suit every instructor and some depend on class size.