Effects of an integrated writing instructional model on Thai EFL University students' essay writing ability and satisfaction

Abstract

This study examined the effects of an integrated Content–Process–Genre (CPG) writing instructional model on Thai EFL university students' essay writing ability and satisfaction. Although research exists on individual writing approaches, empirical evidence on models that unify content-based instruction, process-oriented pedagogy, and genre-based approaches within a single framework remains limited, particularly in Thai EFL contexts. The CPG model distinctively integrates content development, genre awareness, and recursive writing processes into a coherent framework, offering a more comprehensive alternative to conventional EFL writing instruction. A quasi-experimental pretest–posttest control group design was employed with 65 undergraduate English major students at Buriram Rajabhat University, Thailand. The experimental group (n = 36) received instruction through the CPG model, whereas the control group (n = 29) underwent conventional instruction over eight weeks. Writing ability was assessed using an expert-validated analytic scoring rubric across five essay types, and satisfaction was measured via a five-point Likert-scale questionnaire. Independent and paired samples t-tests were used for analysis. The experimental group significantly outperformed the control group on all five essay types — descriptive, narrative, comparison and contrast, cause and effect, and persuasive — at the .05 significance level. Posttest mean scores for the experimental group ranged from 40.80 to 45.36, compared to 34.72 to 36.20 for the control group, with large effect sizes across all essay types (Cohen's d = 1.83–3.47), indicating a substantially meaningful impact on writing performance. Students also reported very high overall satisfaction (M = 4.56, SD = 0.593), with particularly positive perceptions of the revising and editing stage. These findings suggest that the integrated CPG model shows promise for enhancing writing performance and learner engagement by connecting content, genre, and process-oriented practices. The study offers empirical support for the CPG model as a promising instructional framework with pedagogical relevance for university-level EFL contexts.