Differentiation is an umbrella term that applies to multiple different pedagogies. Studies on differentiation often include research on ability grouping, teaching to learning styles, streaming, podding, enrichment, and individualized instruction. In 2018 Marjolein Deunk conducted a meta-analysis on 21 math instruction studies related to the term differentiation. Rather than using one specific definition of differentiation, they searched for studies that included the terms (“adapt* instruct*”, “adapt* teach*”, differentiate*, “individuali* instruct*”, “individuali* teach*”) and 5 more specific terms (“ability group*”, “aptitude treatment”, grouping*, “mastery learning”, streaming).” They found the following results. 

The results of this meta-analysis were low to negative, suggesting little possible benefit of differentiation. But differentiation is an umbrella term, what if we look at the different types of differentiation to see if we get a better result? I conducted a secondary meta-analysis of the topic to get a better picture. Including the data from 6 other meta-analyses and secondary meta-analyses. 

Within this secondary meta-analysis we see multiple high yield effect sizes, including for individualized instruction, RTI, and grade skipping. We also see two effect sizes that are moderately high including  mastery teaching, and peer tutoring. Popular strategies like ability grouping and teaching to learning styles have little meaningful effect. Overall we can see that different types of differentiations, have very different impacts and that what matters is not if we differentiate, but how we differentiate. Indeed as shown in the Deunk 2018 meta-analysis, when these types of interventions are included in the definition of differentiate, the meta-analysis results are low. 


I think it's also interesting to note that the most important forms of differentiation seem to be individual focused, whereas ones that try to group students by ability tend to produce lower results. While individualized instruction does lead to the highest results, grade skipping, RTI, peer tutoring, and mastery teaching, are all forms of differentiation that focus on providing individual students more specific instruction. Whereas ability grouping based interventions, all seemed to fail to produce high results. It appears the individual needs of the child are best served, when we consider the child as an individual, rather than as a part of a group. 

Written by, Nathaniel Hansford

Last Edited 2022-02-27



Steenbergen-Hu, S., Makel, M. C., & Olszewski-Kubilius, P. (2016). What One Hundred Years of Research Says About the Effects of Ability Grouping and Acceleration on K–12 Students’ Academic Achievement: Findings of Two Second-Order Meta-Analyses. Review of Educational Research, 86(4), 849–899. https://doi.org/10.3102/0034654316675417


J, Hattie. (2022). Mastery Teaching. Visible Learning Metax. Retrieved from <https://www.visiblelearningmetax.com/influences/view/mastery_learning>. 


J, Hattie. (2022). Peer Tutoring. Visible Learning Metax. Retrieved from <https://www.visiblelearningmetax.com/influences/view/peer_tutoring>. 


J, Hattie. (2022). RTI. Visible Learning Metax. Retrieved from <https://www.visiblelearningmetax.com/influences/view/response_to_intervention


J, Hattie, (2022). Teaching to Learning Styles. Visible Learning Metax. Retrieved from <https://www.visiblelearningmetax.com/influences/view/matching_teaching_to_style_of_learning>. 


Deunk. (2018). Effective differentiation Practices:A systematic review and meta-analysis of studies on the cognitive effects of differentiation practices in primary education. Educational Research Review, 24, 31–54.