ROBERT MARZANO EXPLAINS THE POWER OF A COMMON LANGUAGE OF INSTRUCTION Marzano has done research on 41 instructional strategies. Below is a document detailing the initial 9. Marzano views the strategies as tools. He states that they be "used as tools to produce results, and if one tool doesn't produce results then you stop using that tool and use a different tool to produce results. Those desired results are positive student learning outcomes.