The research-base for distributing summarizing throughout a lesson is partly based on the Primacy-Recency Effect. David Sousa describes the Primacy-Recency Effect as a “phenomenon whereby, during a learning episode, we tend to remember best that which comes first, second best that which comes last and least that which comes just past the middle” (Sousa, 2011).
To optimize learning, it is important to use the first minutes of a lesson as prime instructional time. It is equally important to maximize the use of the second best learning time, which occurs in the last few minutes of class. Instead of having students work on homework at the end of class, capitalize on this learning time to have students summarize what they have learned.
When the lesson incorporates several distributed opportunities for students to summarize what they have learned throughout the lesson, it leads to greater mastery of the information because the brain has multiple Primacy and Recency points during one lesson.