Marzano’s Instructional Strategies Mitchell New Teacher Cohort January 2008 Categories of Instructional Strategies that Affect Student Achievement Category Ave. Effect Size (ES) Percentile Gain No. of ESs Standard Deviation (SD) Identifying similarities and differences 1.61 45 31 .31 Summarizing and note taking 1.00 34 179 .50 Reinforcing effort and providing recognition .80 29 21 .35 Homework and practice .77 28 134 .36 Nonlinguistic representations