Abstract:
The main objective of the thesis is to find out whether there is any effectiveness in using English free-writing status in Facebook to improve vocabulary mastery. Population of this research is the tenth grade students of SMK N 4 Purworejo in the academic year 2013/2014 that consists of 190 students. The researcher took two classes as sample. They are class X NKPI A as an Experimental Group and X NKPI B as a Control Group. The researcher took quantitative research for analyzing her study. This research used pre-test and post-test as the instrument. The researcher gave pre-test to each group before giving the treatment. For the experimental group, the treatment was given using English free-writing status in Facebook, while for the control group, the treatment was given without free-writing English status in Facebook. At the end of the experiment, both groups were given a post-test. The result of the study showed that there is a difference between mean of experimental group and control group. From the calculation of test, it can be known Value was 88.50>70.87, in other words, the use of English free-writing status in Facebook is effective.
Based on the data, the researcher concludes that teaching vocabulary by using English free-writing status in Facebook is effective to improve vocabulary mastery. As the fact, the result of t-value is 8.2. Based on the 5% significance levels, the value of t-table is 2.008. The result of computation shows that t-value is higher than t-table, which is 8.2>2.008. Another fact shows that the method used is effective is shown by the mean of experimental group that is higher than the mean of control group. In the experimental group, the mean is 88.50 on the contrary, the mean of control group is 70.87.