Effects of EPIRIS Model-Based Instructional Innovation on Thai Primary Students’ English Tense Learning

Abstract

English tense acquisition remains a persistent challenge for Thai primary school students in EFL contexts, where traditional grammar-translation methods have proven inadequate in fostering durable form-meaning connections and active language practice. This study investigated the effects of EPIRIS model-based instructional innovation on primary students’ achievement, motivation, and perceptions related to learning English past tenses, while examining relationships between student motivation, engagement, interaction, and learning outcomes. An explanatory sequential mixed-methods design was employed with 86 participants comprising 66 primary students aged 9–12 and 20 English teachers from 10 schools in Samut Sakhon province, Thailand. The intervention consisted of a 12-hour EPIRIS-structured program delivered over two weeks, incorporating six sequential steps: elicitation, presentation, innovation use, retention practice, interaction, and summary and assessment. Data collection included pretest-posttest measures; validated questionnaires assessing motivation, engagement, and interaction; and semi-structured interviews with purposively selected participants. Results demonstrated significant improvements in student achievement with a mean gain of 6.11 points out of 20 possible points (p < .001). Participants reported high levels of motivation (M = 3.71), engagement (M = 3.64), and interaction (M = 4.60) with strong positive correlations among these constructs (r = .769 to .799). Qualitative analysis revealed three major themes: transformation from passive to active learning, enhanced collaborative learning and peer support, and reduced anxiety with increased confidence. The EPIRIS model demonstrated substantial effectiveness in improving both cognitive and affective outcomes in primary EFL grammar instruction, providing initial evidence for adopting systematic, interactive, pedagogical approaches in English language education.