WhatsAPP Messenger as Media to Teach English

The research consists of two variables, independent variable WhatsApp Messenger and dependent variable is writing ability. The purpose of this research is to find out whether or not there is the significant effect of writing ability as media on Grade Ten Students' Writing Ability in Narrative Text at SMK Tunas Markatin in Academic Year 2017/2018. The instrument used to collect data was post-test form essay. The question item in instrument, numbering 5 items, were prepared and constructed by the researcher, developed from the indicators of writing ability as specified in the blue prints. To obtain good instrument, the question item were tried out to the class other that the sample classes. The instrument was analyzed to know is validity, reliability, discrimination power and difficulty index by using Microsoft Excel 2007. The population of this research is the grade ten students SMK Tunas Markatin in Academic Year 2017/2018 which consist of 97 students the research sample were taken by means of Cluster Random Sampling from the population, represented, in this research by class X AKA 1 as Experiment class and X AKA 2 as Control Class, with the total number of 68 students.