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¶

Claim · All claims
Evidence · 1 study (2 entries) · causal r? · q2
Currency · newest study 2014 · checked against its sources 2026-10-16 (automated, 2 of 2 entries) · not reviewed by a person

Subclaims¶

q2 i? Under sorting, the grades and pass rates of high-skilled students decline while the grades of low-skilled students improve. → Elaine Allensworth and Takako Nomi 2014 q2 i? Students with slightly above-average achievement become the lowest-skilled students in their sorted class, which makes a big difference for their performance. → Elaine Allensworth and Takako Nomi 2014 (2)

Evidence¶

Elaine Allensworth and Takako Nomi 2014¶

Elaine Allensworth and Takako Nomi. (2014). Skill-Based Sorting in the Era of College Prep for All. University of Chicago Consortium on Chicago School Research. https://consortium.uchicago.edu/publications/skill-based-sorting-era-college-prep-all-costs-and-benefits

q2 · i? · causal · r?

The report's comparison of sorted versus de-sorted algebra classes found a divergence between outcome types: "the grades and pass rates of high-skilled students decline, while the grades of low-skilled students improve." No statistics are printed in the release.

"However, sorting by ability has different effects on test scores than on grades and pass rates; the grades and pass rates of high-skilled students decline, while the grades of low-skilled students improve."

Elaine Allensworth and Takako Nomi 2014 (2)¶

Elaine Allensworth and Takako Nomi. (2014). Skill-Based Sorting in the Era of College Prep for All. University of Chicago Consortium on Chicago School Research. https://consortium.uchicago.edu/publications/skill-based-sorting-era-college-prep-all-costs-and-benefits

q2 · i? · causal · r?

The report identifies a middle group harmed by sorting: "students with slightly above-average achievement" become the lowest-skilled in their class, and the release states this makes a big difference for their performance, with no effect size printed.

"Sorting causes students with slightly above-average achievement to be the lowest-skilled students in their class, which makes a big difference for their performance."

Discussion¶

Learner Variables¶

• General Cognitive Ability — moderator: an instructional effect differs with it

Related Claims¶

• Between- or within-class homogeneous ability grouping has a small negative effect on low-ability primary students but no effect on other students — the general claim this finding bears on, with the studies behind it

• 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 — the general claim this finding bears on, with the studies behind it

• How students are sorted into classrooms by skill level can affect their achievement as much as the content they are taught — related
• Fish pond effects: above-norm students became more likely to fail algebra when their skills were low relative to classroom peers after sorting — related
• Below-norm students' algebra test scores improved despite having lower-skill peers post-policy, consistent with additional supports offsetting compositional decline — related
• Below-norm students' pass rates improved post-policy because their skills relative to classroom peers improved under sorting — related
• Algebra failure rates rose post-policy for above-norm students (~3 percentage points) but fell for below-norm students (~4 points); classroom environment and peer ability explained most of the above-norm rise but not the below-norm fall — related
• Failure rates increased and grades declined for higher-skill students in single-period algebra after the policy — related
• The double-dose algebra policy adversely affected non-targeted above-norm students: their algebra grades declined and failure rates increased post-policy — related
• Double-dose algebra policy increased academic demand for both high- and low-skill students, with below-norm students' gains not attributable to peer ability changes — related
• Average test scores are higher when classes are sorted by skill, driven by large learning gains for high-skilled students and slightly lower scores for low-skilled students — related
• Only 64% of Black Michigan students passed Algebra I by 10th grade in 2021-22, below the 74% statewide average, while white students were the sole group above it at 78% — related
• Pre-policy, classroom average ability related positively to test scores but positively to failure, with effects strongest for high-ability students — related
• Policy effects on grades and failure rates differed by incoming ability: most below-norm students' grades improved slightly, but the very lowest-ability students' algebra grades declined — a narrower finding that bears on this claim
• Chicago's double-dose algebra policy raised algebra test scores for both low-skill and high-skill students — related