Examining the effectiveness of targeted morphological instructions on reading outcomes: A randomized controlled trial involving Chinese EFL learners

Previous studies have demonstrated the overall effectiveness of morphological interventions in enhancing word reading and reading comprehension. However, the specific practices within these morphological interventions vary significantly and few intervention studies have investigated how targeted instruction in distinct aspects of morphological awareness can best support word reading and reading comprehension. This research presents the first empirical evidence regarding the relative effectiveness of morphological skills (i.e., morphological analysis and morphological decoding) and affix knowledge in developing English reading-related skills, word reading and reading comprehension among Chinese EFL students. A total of 156 Grade-8 students were randomly assigned to one of three groups: morphological analysis group (experimental group 1), morphological decoding group (experimental group 2) or affix knowledge group (active control group). Both experimental groups received direct instruction on affix knowledge alongside their respective morphological skills. Each intervention consisted of two 50 min sessions per week over a five-week period. The results indicated that all three morphological interventions led to improvements in affix knowledge, inflectional and derivational morphological structure awareness, word reading and reading comprehension. However, no significant differences in improvement were observed among the groups. The findings suggest that the morphological interventions, irrespective of the specific dimensions of morphological awareness taught, were effective for EFL learners. The implications for future research and practice are discussed. Copyright © 2025 The Author(s).