حسن سودمندافشار

The main aim of the present study was to evaluate the effect of morphological awareness instruction on the Iranian third grade high school students' vocabulary size development with gender as a moderating variable. Besides, this study sought to examine the difference in the effect of analytic (morpheme identification) and synthetic (morphological structure awareness) word formation approaches on EFL learners' morphoogical awareness. To this end , 66 (32 male and 34 female) students studying natural sciences and mathematics in Qorveh city in Kurdistan province took part in this study by completing the researcher adapted version of vocabulary Size Test (VST) primarily developed by Nation and Beglar (2007), and the Morphological Awareness Test (MAT) developed by McBride-Chang et al. (2005). The subjects had been selected via convenience sampling and were assigned into two groups-experimental (32students, 16 male and 16 female) and control (34 studnets, 16 male and 18 female). Using Chronbach's Alpha and factor analysis, the instruments were found to have acceptable reliability and validity rates. The experimental group received the instruction on morphological awareness, whereas the control group did not receive this instruction. The resuls of Two-Way ANOVA revealed that morphological awareness instruction had a statistically significan positive effect on the Iranian high school students' vocabulary size development. Furthermore, the results indicated that gender had no significant effect on the Iranian high school students' vocabulary size development. Moreover, the findings showed that the interaction of morphological awareness instruction and gender had no significant effect on the Iranian high school students' vocabulary size developlment.