Short- And Long-Term Word Clustering Effect on Vocabulary Learning of EFL Learners: A Case of Semantic Versus Phonological Clustering

Research on word clustering effect has been a critical issue in vocabulary studies and has generated controversial results. To remove this controversy, the aim of this study is to probe into the effect of word clustering method on vocabulary learning of Iranian EFL learners through semantic versus phonological clustering. To this effect, 80 homogeneous students from four intermediate classes at an English institute in Torbat‑e‑Heydariyeh participated in this research. They were assigned to four groups according to semantic versus phonological clustering (± semantic, ± phonological); then, based on each group's clustering pattern, 10 selected words were taught. At the end of the treatment phase, immediate and delayed posttests of vocabulary were given to the students in a multiple-choice format to investigate the effects of word clustering in short and long-term vocabulary learning. The analysis of the data was done in SPSS through a one-way ANOVA. The results in both immediate and delayed post-tests showed a statistically significant difference among groups. The obtained mean scores revealed the following rank order of mean performance in both immediate and delayed post-tests :(+ semantic, + phonological), (+ semantic, - phonological), (- semantic, + phonological), and (- semantic, - phonological). This finding revealed that semantic and phonological clustering were effective methods of grouping new vocabulary. These findings and relevant implications are discussed in the paper.