Multiple Intelligences as a Pedagogical Heuristic for EFL Argumentative Writing in Ethiopian Higher Education (Original Article)

Abstract This study investigated how Multiple Intelligences Theory (MIT), critically reconceptualised as an instructional design heuristic rather than a validated cognitive model, influences argumentative writing skills among EFL students at an Ethiopian university. Employing a mixed-methods quasi-experimental design, 90 Jimma University undergraduates were randomly assigned to either an experimental group receiving MIT-heuristic instruction (n = 45) or a control group receiving traditional instruction (n = 45). Quantitative data from pretest and post-test argumentative essays were scored independently by six trained raters using a validated analytical rubric demonstrating excellent inter-rater reliability (ICC = 0.92). Independent-samples and paired-samples t-tests were conducted to examine within-group and between-group differences. Qualitative data from 15 post-intervention semi-structured interviews were analyzed using reflexive thematic analysis following Braun and Clarke's six-phase framework. Results revealed statistically significant improvements in writing performance for the experimental group (pre-test M = 2.33, SD = 0.54; post-test M = 3.58, SD = 0.52; t (44) = 12.29, p<.001, η2=.72), whereas the control group showed minimal, non-significant change (M gain = 0.02, p=.061). Between-group post-test comparisons confirmed significant differences favoring the experimental condition (t (88) = 12.28, p<.001, Cohen's d = 2.59). Qualitative findings indicated that MIT-heuristic activities enhanced learner engagement, self-efficacy, and structural command of argumentation by providing diverse, scaffolded entry points into the writing process. When deliberately operationalized as a heuristic for designing varied learning tasks, MIT offers a practical, context-sensitive framework for differentiated writing instruction. The study recommends integrating such heuristic approaches into EFL teacher education and curriculum development to foster inclusive, learner-centred pedagogy in resource-constrained settings.