A practice-framework article, quoting Johnston and Wildy (2016), reports that the literature generally finds attainment grouping (streaming) harms learning outcomes, while noting the research is contested¶

Claim · All claims
Evidence · 1 study · theoretical r? · q1
Currency · newest study 2021 · checked against its sources 2026-10-20 (automated, 1 of 1 entry) · not reviewed by a person

Subclaims¶

q1 i? The literature generally shows that streaming, setting or tracking based on attainment impacts negatively on student learning outcomes, with the greatest disadvantages for lower-achieving students. → Marks 2021

Evidence¶

Marks 2021¶

Marks, A., Woolcott, G., & Markopoulos, C. (2021). Differentiating Instruction: Development of a Practice Framework for and with Secondary Mathematics Classroom Teachers. International Electronic Journal of Mathematics Education, 16(3), em0657. https://doi.org/10.29333/iejme/11198

q1 · conceptual practice-framework article · i? · theoretical · r?

A conceptual article that develops a differentiated-instruction practice framework for secondary mathematics teachers; it does not itself review or synthesise grouping studies. In its introduction it quotes Johnston & Wildy (2016, p. 42) that "the literature generally shows that streaming impacts negatively on student learning outcomes", and states that streaming may have a more significant negative impact on lower-achieving students. No effect size is printed.

"While research is contentious and often contested, the literature generally shows that streaming impacts negatively on student learning outcomes."

Studies bearing on this claim¶

Does grouping learners by attainment (streaming, tracking, homogeneous groups) help or harm their learning compared with mixed groups? This table gathers the studies behind this claim and the 5 narrower claims that bear on it: 6 distinct studies (3 causal, 2 theoretical, 1 review), q1–q3, 0 of 6 with an effect size coded. One row per study, codes as each entry records them; no effect is averaged and no verdict is drawn. Built by scripts/synthesize_claim.py from eval/synthesis/; a row that looks wrong is fixed on the claim it comes from.

Discussion¶

Related Claims¶

• A practice-framework article reports, citing Boaler and Staples (2008), that students in heterogeneous mathematics classrooms learn more, enjoy mathematics more and reach higher understanding than in streamed settings — a narrower finding that bears on this claim
• Heterogeneously grouped teams show more benefits than homogeneously formed teams — a narrower finding that bears on this claim
• Homogeneous grouping for reading instruction and heterogeneous grouping for discussion groups each serve distinct purposes — related
• Sorting by ability affects grades and pass rates differently from test scores: high-skilled students' grades and pass rates decline while low-skilled students' grades improve — related
• Below-norm students' algebra test scores improved despite having lower-skill peers post-policy, consistent with additional supports offsetting compositional decline — related
• In one Chicago study, above-norm students' post-policy algebra test gains were partly explained by higher peer ability and by having classmates who took support algebra — related
• Streaming restructured musician economics before generative AI, with per-stream payouts of fractions of a cent — related