This article presents two empirical studies investigating the extent to which general English proficiency (GEP) and selected learner dispositions in online learning maintain their predictive utility for academic success in English-medium instruction (EMI) contexts in Türkiye across the pre-pandemic, pandemic, and post-pandemic periods. Both studies sampled engineering students from a large public university, with Study 1 involving 474 participants and Study 2 including 460. Study 1 examined the predictive roles of GEP, online learning readiness, beliefs, and satisfaction during the pre-pandemic and pandemic periods. Findings showed that GEP was a significant predictor of academic success before the pandemic, but this predictive relationship was statistically disrupted during the pandemic period. Study 2 extended the analysis to the post-pandemic context, where EMI courses were delivered both face-to-face and online. Results revealed a reinstatement of GEP’s predictive power in face-to-face EMI settings, while readiness, beliefs, and satisfaction with online learning were stronger predictors in online courses. This fluctuation illustrates a ‘passing cloud effect’, in which the predictive weight of language proficiency temporarily wanes under extraordinary contextual conditions but resurfaces when structured environments return. Based on the findings, several pedagogical implications are provided, and some relevant suggestions are made, underscoring the fluctuating nature of academic success in EMI.
Soruç et al. (Sun,) studied this question.