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

<title>Abstract</title> <p> This study examined the effects of Multiple Intelligences Theory (MIT), reconceptualized as an instructional design heuristic rather than a validated cognitive model, on argumentative writing skills among EFL learners at an Ethiopian university. A mixed-methods quasi-experimental design assigned 90 undergraduates to an experimental group receiving MIT-heuristic instruction ( <italic>n</italic>  = 45) or a control group receiving traditional instruction ( <italic>n</italic>  = 45). Writing performance was assessed via pretest and post-test argumentative essays, independently scored by six trained raters using a validated rubric (ICC = 0.92). Quantitative analyses employed independent-samples and paired-samples <italic>t</italic> -tests. Qualitative data from 15 semi-structured interviews underwent reflexive thematic analysis (Braun &amp; Clarke, 2021). Results revealed statistically significant improvements in the experimental group (pretest <italic>M</italic>  = 2.33, <italic>SD</italic>  = 0.54; post-test <italic>M</italic>  = 3.58, <italic>SD</italic>  = 0.52; <italic>t</italic> (44) = 12.29, <italic>p</italic> &lt; .001, η² = .72), whereas the control group showed minimal non-significant change ( <italic>M</italic> gain = 0.02, <italic>p</italic> = .061). Between-group post-test comparisons confirmed significant differences favoring the experimental condition, <italic>t</italic> (88) = 12.28, <italic>p</italic> &lt; .001, Cohen's <italic>d</italic>  = 2.59. Qualitative findings corroborated these outcomes, indicating that MIT-heuristic activities enhanced engagement, self-efficacy, and structural command of argumentation by providing scaffolded entry points into the writing process. When operationalized as a heuristic for designing varied learning tasks, MIT offers a practical, context-sensitive framework for differentiated writing instruction. The study contributes to EFL pedagogy in resource-constrained, large-class settings and recommends integrating such heuristic approaches into teacher education and curriculum development to foster inclusive, learner-centred instruction. Future research should pursue replication across diverse contexts, include delayed post-tests to assess long-term retention, and employ direct affective measures to validate the proposed mechanisms underlying the observed effects. </p>