Abstract
The present study compared the effectiveness of contextualized, decontextualized, and glossing on learners’ short-term and long-term vocabulary retention in an EFL context. To carry out the study, 66 male senior high school students at intermediate language proficiency level were selected from four intact classes. A proficiency test was administered to all participants to assure their homogeneity in language proficiency. Then, the classes were assigned into four groups including three experimental groups, i.e., the decontextualized group, the contextualized group, the glossing group, and a control group. After receiving five sessions of treatment, a vocabulary test was administered as the posttest to all the four groups once in order to assess their short-term retention and once 16 days later as a delayed posttest to assess their long-term retention of vocabulary. Two separate ANOVAs were run on the collected data which lent weight to the positive effect of the treatment on the students’ long-term retention of vocabulary. The results revealed that the experimental groups outperformed the control group. Also, regarding the short-term retention, no significant difference was found between the experimental groups and the control group. Finally, it is highly recommended that language teachers and syllabus designers introduce this contextualized instruction to the learners to encourage a more interactive way to make sense of the text and consequently improve the students’ long-term retention of vocabulary.