Project-Based Learning and Scientific Literacy in Primary Science: Quasi-Experimental Evidence from Grade 4 Students in North Sulawesi

Abstract

Objective: This study examined whether Project-Based Learning (PjBL) was associated with higher scientific-literacy achievement and greater learning gains among Grade 4 students studying pollination and seed dispersal. Method: A quasi-experimental nonrandomized control-group pretest-posttest design involved two intact classes in a public primary school in Tomohon, Indonesia (N = 40; 20 students per condition). Scientific literacy was assessed with a 20-item form selected from a 30-item pilot pool; the pilot pool showed Cronbach's alpha = .880. Analyses emphasized paired-samples t tests, Welch independent-samples t tests, mean differences, 95% confidence intervals (CIs), and Hedges' g. Results: Baseline performance was closely similar (M = 67.15 vs. 67.75; g approximately -0.08). The PjBL class increased to M = 85.35 (mean gain = 18.20), whereas the comparison class increased to M = 78.35 (mean gain = 10.60). At posttest, the PjBL class scored 7.00 points higher, Welch's t(31.64) = 5.139, p < .001, 95% CI [4.22, 9.78], g = 1.59, 95% CI [0.88, 2.31]. Gain scores differed by 7.60 points, Welch's t(37.26) = 3.591, p = .001, 95% CI [3.31, 11.89], g = 1.11, 95% CI [0.44, 1.78]. Novelty: The study provides effect-size-informed, context-specific evidence on Grade 4 scientific literacy while limiting inference to the two observed intact classes rather than claiming a broadly generalizable causal effect.