Mother-Tongue Instruction as a Catalyst for STEM Learning Outcomes and School Retention in Sub-Saharan Africa: A Longitudinal Quasi-Experimental Study
DOI:
https://doi.org/10.63569/ajopac/08/01/08Keywords:
mother-tongue instruction; STEM education; oral reading fluency; school dropout; sub-Saharan Africa; language-in-education policyAbstract
In sub-Saharan Africa, 89% of children cannot read a simple text with comprehension by age 10, and most receive
instruction in colonial languages—English, French, or Portuguese—rather than their mother tongues. This paper
investigates whether Mother-Tongue Instruction (MTI) measurably improves Science, Technology, Engineering, and
Mathematics (STEM) achievement and reduces school dropout. Using a six-year longitudinal quasi-experimental
design across six sub-Saharan African countries—Kenya, Ghana, Tanzania, Uganda, Zambia, and Senegal—the study
tracks 4,500 primary school students (2,226 in the MTI cohort; 2,274 in the control group) and 330 teachers from
2018 to 2023. Outcomes include oral reading fluency (ORF) measured in correct words per minute (cwpm), science
comprehension scores (%), annual school dropout rates (%), and teacher pedagogical confidence assessed on a
validated 100-point scale. Data were drawn from Early Grade Reading Assessment (EGRA) protocols, school
administrative registers, and the Teacher MTI Pedagogical Confidence Scale (TMPCS). Analysis employed fixed
effects panel regression, with mediation analysis to assess the reading-to-science pathway. By 2023, MTI students
reached a mean oral reading fluency of 61.3 cwpm, compared with 29.6 cwpm in control schools (d = 1.64). Science
comprehension scores in MTI schools rose from a mean of 37.5% to 64.6% over the study period—a gain of 27.1
percentage points—substantially above the marginal improvement in control schools. Annual dropout rates in MTI
schools fell from 30.1% to 13.9%, while in control schools they remained essentially stable, at 29.2% to 26.2%.
Teacher confidence improved by a mean of 31.8 points on the TMPCS (82.4% gain), with Senegal and Zambia
recording the largest relative increases. Mediation analysis found that 47% of the MTI effect on science
comprehension was mediated by gains in reading fluency. These findings are situated within published evidence from
the PRIMR Initiative in Kenya (Piper et al., 2016), the Ethiopian mother-tongue reform (Seid, 2016), and the PASEC
2019 assessment (PASEC, 2020), and carry direct implications for language-in-education policy, STEM curriculum
design, and teacher education reform across the continent.
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