Interactive Segments
There is a wide range of possibilities for interactive activities that can be interspersed with lecture segments. Any of these general suggestions for interactive segments could be developed into short think-pair-share questions or activities, ConcepTests, the Question of the Day, or longer activities. These possibilities are not exclusive and can be combined in various ways.
Interpretation of graphs
Give them real data, as a graph for a short question or to plot themselves as part of a longer exercise. Have them summarize and interpret any patterns they can find.
Making calculations and estimations
Give the students some real data, and have them summarize them mathematically before moving on to interpretation.
Predictions of demonstrations
This is discussed in other Starting Point modules, particularly the page on teaching with interactive demonstrations.
Brainstorming
Especially handy for assessing prior knowledge of a topic, this can be done quickly by individuals (have them write their ideas on an index card) or groups working together.
Tying ideas together
After covering several topics, let the students try and synthesize big ideas from them before you start to do so through lecture. More straightforward syntheses can be done with short questions, or if they need time for reflection, group projects.
Applying what has just been learned in class or reading to solve a problem
It's very important to make sure that students can connect abstract ideas with specific real examples, especially slightly complicated ones.
Collecting student responses
Think about how you will end an interactive activity, gathering student responses and providing, when appropriate, a synthesizing discussion or follow-up assignment. The student responses also provide useful feedback about what students have learned.
Learn more about collecting, assessing, and responding to feedback
Further Reading
Interactive Lectures: summaries of 36 formats (more info) : A number of different ideas for in-class exercises and advice on using them.