This study examined the effectiveness of the Context-Adaptive Learning Model (CALM) integrated with Task-Based Language Teaching (TBLT) in enhancing the English speaking skills and classroom engagement of Thai lower-secondary students. CALM is a five-competency framework — diagnostic competency, didactic competency, classroom management, subject matter knowledge, and contextual awareness with reflective practice — that guides teachers in adapting instruction to the linguistic and socio-cultural context of their learners. A classroom action research design comprising three plan–act–observe–reflect cycles was implemented with 20 Grade 8 students at a municipal school in Khon Kaen Province, Thailand, during the first semester of the 2025 academic year. Six CALM–TBLT lesson plans organised around occupations, food and restaurant ordering, and daily routines were delivered across the three cycles. Data were collected through a speaking pre-test and post-test scored with a four-criterion analytic rubric, an end-of-cycle speaking performance assessment, a 12-item perception and engagement questionnaire, and open-ended written responses. Descriptive statistics, a paired-samples t-test, a repeated-measures ANOVA and content analysis were used. Speaking scores increased from M = 12.55 (SD = 3.62) to M = 16.45 (SD = 3.03) out of 20, a statistically significant gain, t(19) = 8.51, p < .001, with a large effect size (Cohen’s d = 1.90). Eighty-five per cent of students reached the 70 per cent criterion, exceeding the 70 per cent target set for the study, and cycle means rose steadily. Perception and engagement were high (M = 4.05, SD = 0.55), and qualitative data showed gains in motivation, confidence and willingness to speak.
Keywords: Context-Adaptive Learning Model; Task-Based Language Teaching; English speaking skills; adaptive teaching competency; classroom action research