THE EFFECT OF PROCESS GENRE APPROACH AND VOCABULARY MASTERY ON THE STUDENTS WRITING ACHIEVEMENT

This study was quantitatively conducted to discover whether Process Genre Approach had effects on the students achievement in writing expository texts. By controlling the effect of vocabulary mastery, this study was also conducted to investigate the interaction effect of both independent variables. The population was Grade XI students of State Senior High School (Sekoiah Menengah Atas Negeri: SMAN) 2 Kisaran 2008-2009 School Year. There were seven classes. Each class consisted of 32 students. Sample of this research was two classes divided into two groups representing the high and low level of vocabulary mastery. Ten students were randomly assigned to represent each group. The experimental group was taught with Process Genre Approach and the control one with Conventional Approach. The data collected were analyzed with two ways analysis of variance (2x2 ANOVA). The findings indicated the significant F- ratio between approaches, where F observed (6.12) was greater than F table (4.11) at the 0.05 level of significance. It was also found that F observed between rows (vocabulary mastery) was greater than the F table at the level of .05 and .01 namely, F observed (14.76) was greater than F table (4.11) or F table (7.39). Therefore. the first and second null hypotheses were rejected. The findings also show that F-ratio interaction was not significant. The F observed (0.00025) was lower than F table (4.11). Therefore, the third null hypothesis was accepted. Based on the findings, it is suggested that Process Genre Approach should be applied in English instruction to develop the students writing achievement.