Assisting Students Struggling with Mathematics: Intervention in the Elementary Grades (WWC Practice Guide 2021006)
What Works Clearinghouse expert panel (Fuchs, L. S., chair) · 2021
grade Breviewdeveloper-involvedreplicatednumbers spot-checked
Sample
Rec 1: ~43 studies; Rec 6: 27 studies (all WWC-standards)
Population
K-6 students struggling with mathematics.
Design
All six recommendations rated STRONG evidence. Panel chaired by Lynn Fuchs, whose trials populate the corpus — discount modestly for incumbency; the corpus is real RCTs.
Key findings
The current institutional consensus: explicit/systematic instruction for struggling students gets the top rating (the most replicated finding in math intervention research), and brief timed fluency activities are affirmatively recommended with Strong evidence — the official counterweight to anti-timed-test advocacy.
Genetic confound
Underlying studies experimental; targets ability-selected strugglers.
Replication notes
The explicit-instruction-for-strugglers recommendation has survived three federal review cycles with strengthening ratings.
Effects
| Outcome | Metric | Value | Measure | Timing | Vs | Horizon | Class |
|---|---|---|---|---|---|---|---|
| Systematic (explicit) instruction (Rec 1) | WWC rating | Strong (~43 studies) | mixed | end-of-treatment | business-as-usual | end-of-treatment | domain-skill |
| Timed activities to build fluency (Rec 6) | WWC rating | Strong (27 studies) — directly contradicts the anti-timed-test movement | mixed | end-of-treatment | business-as-usual | end-of-treatment | domain-skill |
| Concrete/semi-concrete representations (Rec 3) | WWC rating | Strong | mixed | end-of-treatment | business-as-usual | end-of-treatment | domain-skill |
Cited by
- Explicit vs reform/constructivist math instructionmoderate supportconf: highgc: low
- Manipulatives and concrete-representational-abstract (CRA) sequencesmoderate supportconf: mediumgc: low
- Math-fact fluency and timed practice (and the anti-timed-test claims)strong supportconf: highgc: low