Modeling the impact of digital PBL and GI on students’ argumentative writing: SEM of critical thinking, self-efficacy and engagement

Purpose This study modeled the impact of digital problem-based learning and group investigation (PBL-GI) instruction on argumentative writing performance, examining the mediating roles of critical thinking, writing self-efficacy and student engagement. Design/methodology/approach A cross-sectional survey design employed structural equation modeling with 724 Indonesian English as a Foreign Language (EFL) university students who completed validated instruments measuring all constructs. Writing performance was assessed through standardized argumentative essay tasks scored by trained raters. Findings The structural model demonstrated excellent fit (comparative fit index (CFI) = 0.95, root mean square error of approximation (RMSEA) = 0.030) and explained 67% of variance in writing performance. Digital PBL-GI instruction showed significant direct effects on writing performance (ß = 0.34, p < 0.001) and strong indirect effects through critical thinking (ß = 0.19), writing self-efficacy (ß = 0.20) and engagement (ß = 0.16). The total effect was substantial (ß = 0.75). Research limitations/implications Findings support constructivist learning theory and demonstrate that integrated pedagogical approaches with digital technologies enhance writing through multiple psychological pathways. Practical implications The study provides empirical evidence for implementing digital PBL-GI instruction in EFL writing curricula, highlighting the importance of simultaneously addressing cognitive and affective dimensions in writing pedagogy. Originality/value The study’s unique contribution lies in its comprehensive integration of instructional variables with psychological mediators through advanced statistical modeling, providing the first large-scale structural analysis of these relationships in EFL writing contexts. The practical implications suggest that effective writing instruction must move beyond traditional approaches toward student-centered, problem-based methodologies that leverage digital technologies while simultaneously addressing cognitive, metacognitive and affective dimensions of learning.