A recent meta-analysis evaluated the effectiveness of interventions for elementary students with math difficulties. To be included in the review, studies had to use randomized or quasi-experimental designs and evaluate word-problem solving interventions.
A total of 52 studies were included in the review. Overall, results showed a significant positive effect for mathematics outcomes (ES = +1.01), with a high variability suggesting the presence of factors influencing the effect. By analyzing these factors, the results showed a larger effect when the students involved had only math difficulties (ES = +1.04) compared to both math and reading difficulties (ES = +0.66). When the intervention was delivered in large groups (more than 8 students), the effect was larger than for one-to-one or small-groups (ES = +1.41, +0.86, respectively). Intensive interventions (3 to 5 times a week) were more effective than interventions implemented one or two times weekly (ES = +1.15, +0.76, respectively). A difference was also found for instructional model: interventions involving general heuristics were more effective than the ones based on schema-based instruction (ES = +1.18, +0.71, respectively).
