This study was aimed at finding out: (1) whether there is a significant difference in writing skill between students taught using Interactive Writing and students taught using Guided Writing; and (2) whether Interactive Writing is more effective than Guided Writing to teach writing. The research method used in this study is a quasi-experimental research design. This research was conducted at SMP N 1 Nguter in the academic year of 2015/2016. The population of the research is the eighth grade of SMP N 1Nguter. The samples are class VIII D as the experimental class which consists of 26 students and class VIII E as the control class which consists of 26 students. The research instrument used to collect the data in this study is test. The data were analysed by using t-test formula. The computation of the t-test shows that t observation (to) = 3.766 is higher than t table (50, 0.05) = 1.671. Therefore, it can be concluded that there is a significant difference in writing skill between the students taught using Interactive Writing and the students taught using Guided Writing. The mean score of experimental group is 71.88, while the mean score of control group is 66.46. Therefore, it can be concluded that Interactive Writing is more effective than Guided Writing to teach writing.

Key words: interactive writing, guided writing, writing skill.