An exhaustive search considered hundreds of published and unpublished articles. It included those that met the following criteria:
- Schools or classrooms using each programme had to be compared to randomly assigned or well-matched control groups
- Study duration had to be at least 12 weeks
- Outcome measures had to be assessments of the mathematics being taught in all classes. Almost all are standardised tests or state assessments.
- The review placed particular emphasis on studies in which schools, teachers, or students were assigned at random to experimental or control groups.
Programmes were rated according to the overall strength of the evidence supporting their effects on maths achievement. “Effect size” (ES) is the proportion of a standard deviation by which a treatment group exceeds a control group. Large studies are those involving a total of at least 10 classes or 250 students.
- For the full report, from which this summary was taken, see Slavin, R.E., Lake, C., & Groff, C. (in press), Effective programs in middle and high school mathematics: A best evidence synthesis. Review of Educational Research. There is also an updated version of the full report.
- For a related ‘What Works Clearinghouse’ review of middle school (11-14 years) mathematics curricula and ICT (US), see https://ies.ed.gov/ncee/wwc/FWW
- There is also a related review of primary mathematics programmes by Slavin & Lake (2008).