Hadi Salehi - (English Department, Najafabad Branch, Islamic Azad University, Najafabad)
Akbar Mosayebi - English Department, Najafabad Branch, Islamic Azad University, Najafabad
Bahareh Amiri - English Department, Najafabad Branch, Islamic Azad University, Najafabad

Given the importance of vocabulary in language learning, this study tried to investigate the effectiveness of short message service (SMS) and spacing effect on Iranian intermediate EFL learners’ vocabulary learning and retention. To this end, 60 male and female intermediate learners, aged 17-27, of an English language institute in Isfahan, Iran, randomly selected, were divided into three equal groups, one control group (CG) and two experimental groups (EG1 & EG2) based on the results of a proficiency test, Quick Oxford Placement Test (QOPT). After administering a pretest and during a 10-week treatment, the participants in EG1 received English vocabularies chosen from Oxford Vocabulary Builder book, as well as definitions and example sentences through SMS without spacing and in EG2 with spacing throughout 18 sessions. However, the participants in control group were taught new vocabularies through conventional board and paper technique for the same period. At the end of the treatment, the participants were given a vocabulary posttest and EG1 filled out an attitude questionnaire to see the effect of mobile technology on their vocabulary learning and retention. Then, their pre- and posttest scores were compared using a one-way between-groups ANOVA. The results of vocabulary posttest (.15 <.05) indicated that the three groups did not significantly differ on the posttest. Moreover, 4 weeks after the posttest, they were administered a delayed posttest and EG2 filled out an attitude questionnaire, too. Then, their delayed posttest scores were compared using a one-way between-groups ANOVA. The results of which (.000 < .05) showed that the three groups significantly differed in terms of vocabulary retention after a lapse of time. At the end in order to analyze the attitude questionnaires, one-sample t-test was employed and the results (.000 < .05) for both of them showed that the relevant treatment (the application of spaced SMS for EG2 and the application of SMS for EG1) was viewed to be significantly positive by the learners in EG2 and EG1. The results of this study can have pedagogical implications for language teachers, in that they can use SMS as a useful way of teaching large numbers of vocabularies

mobile learning, SMS-learning, spacing effect, vocabulary learni