The impact of online math programs depends on its implementation, especially in vulnerable populations from developing countries. An existing online platform was adapted, at the request of the Chilean Ministry of Education, to exclusively include exercises previously designed and tested by a paper-based government program for elementary school. We carried out a cluster-randomized controlled trial (RCT) with 50 fourth grade classrooms. Treatment classrooms used the platform in a weekly 90-min math session. Due to a social instability outbreak in the country, a large unexpected disruption with huge absenteeism occurred in the second half of the semester, which turned this study into a unique opportunity to explore the robustness of the platform’s effects on students’ learning. Using multiple imputation and multilevel models, we found a statistically significant effect size of 0.13, which corresponds to two extra months of learning. This effect is meaningful for four reasons. First, it has double the effect of the paper-based version. Second, it was achieved during one semester only. Third, is half that obtained with the platform for a complete year with its own set of exercises and with two sessions per week instead of one. Fourth, it was attained in a semester with a lot of absenteeism.

Objectives: In this tutorial, we examine methods for exploring missingness in a dataset in ways that can help to identify the sources and extent of missingness, as well as clarify gaps in evidence.Methods: Using raw data from a meta-analysis of substance abuse interventions, we demonstrate the use of exploratory missingness analysis (EMA) including techniques for numerical summaries and visual displays of missing data.Results: These techniques examine the patterns of missing covariates in meta-analysis data and the relationships among variables with missing data and observed variables including the effect size. The case study shows complex relationships among missingness and other potential covariates in meta-regression, highlighting gaps in the evidence base.Conclusion: Meta-analysts could often benefit by employing some form of EMA as they encounter missing data.

Artículos originales de investigación educacional sobre temas educativos, nacionales y latinoamericanos. Bilingüe; evaluación ciega de pares; open Access.