Educators educating Educators

Jan 19

Nov 15 Teaching Tip


The Primacy-Recency Effect: People remember best what hapens first, second best what happens last, and least what happens in the middle.

But in the classroom, this presents a problem.  Why?  A biological phenomena called the S-shaped curve!


In last month’s Ed Tips, teaching techniques were presented based on the fact that short-term memory is linked to functional changes in existing synapses, while long-term memory is associated with a change in the number of synaptic connections. The techniques stressed the importance of allowing time in the class period in order for these processes to occur.

This month’s Ed Tips will also focus on a teaching practice based on neuroscience research espoused by William Klemm, Professor of Neuroscience, College of Veterinary Medicine and Biomedical Sciences at Texas A&M University. Klemm is an author of numerous neuroscience-related books with research interest in cognitive neuroscience.

Klemm posits that most biological phenomena create an S-shape curve and the curve applies to a student’s memory. Naturally, before we begin to comprehend the educational implications of how an S-shaped curve affects a student’s learning, we should have an understanding of an S-shaped curve.

A population growth curve is a good example of an S-shape curve. In nature, because there are few breeding individuals, a population will grow slowly at first and then pick up speed. As exponential growth continues, population size grows more rapidly. At some point, however, the population becomes large enough to strain the resources of its environment. Then the curve growth becomes less and less steep, finally reaching a plateau. The population density at which the curve flattens out or where the growth is constant represents the carrying capacity of the environment, a population growth equilibrium caused by the balance between births and deaths.

Below are two diagrams illustrating the S-shaped curve.


S-Shaped curve 1


S-Haped curve B


It is essential to note that the S-shaped curve is exponential and most of the growth occurs in the middle stage.

The diagram below is Klemm’s explanation of how the S-shaped curve relates to teaching.


Klemm The More You Know



How does this apply to education? As illustrated above, there are three stages in a S-shaped curve. Significantly, Klemm notes that the middle stage is the most critical since this is the largest growth area. Educationally however, this presents a problem to a teacher.

This quandary is due to the serial position effect, discovered by Hermann Ebbinghaus in the late 1890s. According to Wikipedia, “the serial position effect is the tendency of a person to recall the first and last items in a series best, and the middle items worst. When asked to recall a list of items in any order (free recall), people tend to begin recall with the end of the list, recalling those items best (the recency effect). Among earlier list items, the first few items are recalled more frequently than the middle items (the primacy effect).” The serial position effect is often referred to as the primacy-recency effect.

Consequently, applying the primacy-recency effect to classroom instruction, students will remember best what is taught first, second best is taught last, and least what is taught in the middle.

And therein lies the problem for a classroom teacher and students. Remembering the principles of the S-shaped curve, the middle of the curve is where the most growth occurs but according to the serial position effect/primacy-recency effect, the middle of a lesson is what is remembered the least.

Primacy-Recency Effect


How to combat the problem? Teachers must design lessons so that the moments in the “middle” of a lesson should be dedicated to student-centered practice. Some activities that will help improve student memory are the use of student learning centers, flexible groups, student-student conversations, students identify similarities and differences in what was previously taught, summarizing & note taking, generating mental images, drawing pictures or pictographs, constructing graphic organizers, making physical models of the content, and generating & testing hypotheses

Additionally, below are two excellent resources for student-centered activities




Finally, the last part of the class should be dedicated to summarizing vital concepts and provide carryover to the next class.




In authentic classroom practice, teachers need to change the person, place, or activity every 10-20 minutes to help improve student’s memory.

I trust that once a lesson is designed with the primacy-recency effect in mind you will notice improved student recall of the intended material.

Have a great November with your students and Happy Thanksgiving!


“If we can control the attention of the child, we solve the problems of education.” Maria Montessori

This month Ed Tip will examine how to improve students' learning by activating their attention.