aural and written vocabulary instruction on less-skilled efl learners' listening comprehension

This study explored the effect of aural and written vocabulary knowledge instruction on the listening performance of less-skilled intermediate english as foreign language (efl) learners. a total of 124 female learners between 14 and 16 years old took the oxford quick placement test (oqpt), and 100 were identified as the less-skilled intermediate efl students learning english in three high schools in iran. then, a true experimental design was employed and they were randomly divided into two experimental groups called written vocabulary instruction (n = 31) and aural vocabulary instruction (n = 33) and a control group called no vocabulary instruction (n = 36). the aural and written vocabulary instruction groups received aural and written vocabulary treatment respectively for 6 sessions, while the control group followed a regular classroom approach without additional vocabulary instruction. all of the participants were asked to take the key english test (ket) before and after the intervention. a one-way anova and a post-hoc test revealed that the experimental groups had a higher gain with a moderate effect size in terms of listening performance than the control group. in addition, no significant difference was found between the aural and written vocabulary instruction. this can be due to the overreliance on bottom-up processing and word-by-word segmentation, which are the main approaches used by low proficiency efl learners. moreover, iranian efl learners' dependency on vocabulary knowledge can be a result of using grammar translation method of language teaching as the primary method in iranian public schools. results of the present study supports explicit teaching of vocabulary items suggesting teachers and syllabus designers to use pre-listening activities such as vocabulary preparation at the center of listening activities to enhance schema activation and listening comprehension.