Source: Review of Educational Research, 80(3): 372-400. (September 2010).
This systematic review of algebra instructional improvement strategies identified 82 relevant studies with 109 independent effect sizes representing a sample of 22,424 students.
Five categories of improvement strategies emerged: technology curricula, nontechnology curricula, instructional strategies, manipulatives, and technology tools.
All five of these strategies yielded positive, statistically significant results.
Furthermore, the learning focus of these strategies moderated their effects on student achievement. Interventions focusing on the development of conceptual understanding produced an average effect size almost double that of interventions focusing on procedural understanding.