By Jun Wang, Johns Hopkins University
The results of many initially effective academic interventions diminish or fade over time in follow-up studies. A recent study by Drew Bailey, Lynn Fuchs, Jennifer Gilbert, David Geary, and Douglas Fuchs investigated the sustained impacts of Galaxy Math, a first-grade mathematics intervention program for at-risk students, and discussed the potential factors that sustain its effects.
The 16-week intervention is intended to support children’s arithmetic development by targeting the conceptual and procedural bases. The participants were at-risk first-grade students randomly assigned to three groups: a control group (n = 224), a speeded intervention group (n = 211), and a non-speeded intervention group (n = 204). The two intervention groups received identical conceptual instruction in the first 25 minutes, but different forms of practice in the last 5 minutes.
The results revealed that at the end of first grade, both intervention groups significantly outperformed the control group on all first-grade outcome measures (speeded: ES=+0.24-0.90; non-speeded: ES=+0.20-0.51). However, at the second- and third-grade assessments, none of the effects were statistically significant, although several effects still favored intervention groups over the control group.
The authors suggested several explanations for the fadeouts in this intervention: catching up rapidly by the control group after the intervention ended, no follow-up explicit instructional support for the intervention groups, and the implementation of multitier systems of support, in which the control group may have received other types of intervention.
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