The Facts About Ability Grouping

There have been some recent posts in Education Week that discuss the use of ability grouping in classrooms. You can read these articles here, here, and here. It is unfortunate that this outdated practice continues to rear its ugly head. This post is the comment I left on each article, in hope to correct any misconceptions.


Photo Credit: Sean Rogers1 via Compfight cc

I think flexible grouping and ability grouping are getting confused. Ability grouping is defined as putting students into groups based on their perceived overall ability and intelligence. It is not effective. It has an effect size of .12 on student learning. This practice is #121 out of 132 teaching practices (Hattie, 2009). It has shown to have the same impact as a student’s gender and their diet. Knowing this, ability grouping should not generally be used in schools. It is noted by Hattie that ability grouping for gifted students does have a stronger effect on these specific learners (although acceleration is a much more effective practice).

Flexible grouping, on the other hand, is something every classroom should be using. It has its roots in formative assessment (0.9 effect size) and Response to Intervention (1.07 effect size). Flexible grouping is when we continuously assess our students, determine what they need, and response to their needs strategically. This happens in small groups and individually. It is a fluid process. The workshop model, used by expert teachers such as Cris Tovani and Donalyn Miller, allow for flexible grouping to naturally happen. It is harder work, but the right work because it has been shown over time and through many studies to have the most impact on kids. If we believe all students can and want to learn, there is no need for ability grouping anyway.

To apply a quote by Mark Twain to this topic, the difference between flexible grouping and ability grouping is the difference between lightning and a lightning bug.


Hattie, John (2009). Visible Learning: A Synthesis of Over 800 Meta-Analyses Relating to Achievement. New York: Routledge.

Miller, Donalyn (2009). The Book Whisperer: Awakening the Inner Reader in Every Child. San Francisco: Jossey-Bass.

Tovani, Cris (2011). So What Do They Really Know? Assessment That Informs Teaching and Learning. Portland, ME: Stenhouse.

Author: Matt Renwick

Matt Renwick is an 18-year public educator who began as a 5th and 6th-grade teacher in Rudolph, WI. He now serves as an elementary principal for the Mineral Point Unified School District ( Matt also teaches online graduate courses in curriculum design and instructional leadership for the University of Wisconsin-Superior. He tweets @ReadByExample and writes for ASCD ( and Lead Literacy (

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