What One Hundred Years of Research Says About Ability Grouping and Acceleration for Students K-12

Most parents would tell you they want to see their children participating in academic programs, whose practices are proven, though research, to be beneficial and effective. One such practice is known as ability grouping and it involves placing students into classes or small groups, either within the same class, grade or across multiple grades, based on their readiness for content, prior achievement in an area, or ability levels. The aim here is to match the curriculum and instruction to the learning needs and abilities of the student.

A similar practice is known as academic acceleration and is often referred to as skipping a grade, advanced placement in a particular subject, or early entrance to some level of schooling (e.g. early entrance to first grade). This approach takes the same aim at matching a student’s level of ability with the appropriate level of instruction. The effects of these practices have been an issue of great interest to many educators for over a century.

A recent study published in the Review of Educational Research, provided new evidence that K-12 students do indeed benefit from various forms of ability grouping and acceleration, in terms of their academic achievement. The study, “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”, was conducted by Saiying Steenbergen-Hu and Paula Olszewski-Kubilius, two researchers from Center for Talent Development (CTD) at Northwestern University, and Matthew Makel of Duke University’s Talent Identification Program (Duke TIP). The authors comprehensively reviewed nearly 100 years of research, covering 172 empirical studies on the efficacy of ability grouping, as well as 125 studies on acceleration.

The research and review found the following:

• In comparison to their peers who received traditional non-ability-grouped instruction, students benefited from within-class grouping, which often involves teachers assigning students to several small homogeneous groups for instruction based on prior achievement or learning capacities.
• The benefits were even greater when students were grouped across grade levels for specific subjects, especially reading, and when high-achieving and gifted students were grouped together for instruction.
• Students who accelerated their learning through various methods, such as skipping grades, taking Advanced Placement (AP) courses and exams, or entering school or college earlier, significantly outperformed their non-accelerated peers of the same age, and performed just as well as older students who were not accelerated.

Strong research exists to support grouping and acceleration, yet these practices are currently underutilized within schools. The authors of this study hope the findings will increase educators’ confidence in employing grouping and acceleration strategies to meet the learning needs of academically advanced learners.