The Effectiveness of Using Tumblr Blog for Teaching Writing Descriptive Text | Sultan Ageng Tirtayasa University 1 THE EFFECTIVENESS OF USING TUMBLR BLOG FOR TEACHING WRITING DESCRIPTIVE TEXT (AN EXPERIMENTAL STUDY CONDUCTED IN A SENIOR HIGH SCHOOL AT 10 TH GRADE STUDENTS OF SMKN 1 KOTA SERANG) Rifki Handayani S-1 English Department, Teacher Training and Education Faculty Sultan Ageng Tirtayasa University, Indonesia rifkihandayani@gmail.com ABSTRACT The objective of this research is to find out whether or not Tumblr Blog is effective for teaching writing descriptive text at 10 th grade students of SMKN 1 Kota Serang. The researcher used quantitative method by applying true experimental design. The population of this research were the tenth grade students of SMKN 1 Kota Serang which consist of seven majors of study. The researcher took 40 students in experimental class and 40 students in control class as samples by using cluster sampling. The experimental class in this research is X Multimedia 1 and the control class is X Multimedia 2. The researcher used the test as the research instrument, the test consist of pre-test and post-test, and the technique of the test is written test. Moreover, the researcher used content validity to know the validity of the test, and inter rater realiability of instrument. Then, after collecting the data, the researcher analyzed them by using T-test. The result of the research showed that Tumblr Blog gave a significant effect on students’ writing descriptive text in experimental class. It can be seen from the result of T-test calculation. The result of T-test told that Tcount is 4.98 while the Ttable is 1.68. This calculation used the significance of 0.05 to determine the value of T-table. So, Tcount > Ttable (4.98 > 1.68). It means that alternative hypothesis (Ha) is accepted, and null hypothesis (Ho) is rejected. So, the use of Tumblr Blog for teaching writing descriptive text at the 10 th grade students of SMKN 1 Kota Serang is effective. Keyword: Web-Blog, Tumblr, Writing, Descriptive Text. INTRODUCTION In Indonesia, English is learnt as a foreign language (EFL). The teaching of English aims at the mastery of four skills namely listening, reading, speaking and writing. Writing seems to be the most difficult one among other skills. As stated by Priyatmojo (2011), that writing is one of the four skills in English considered as the most difficult skill compared to other skills by both teacher and most students. Based on the researcher’s interview with English teacher tenth grades of SMKN 1 Kota Serang, generally the difficulties which are faced by the students in learning writing, they are still confused in getting ideas to start their writing, have difficulties in combining words and paragraphs coherently, and also lack of vocabularies. Moreover, English teacher there rarely uses many media for teaching, even though their school have good facilities. The lack of uses of interesting media make students seems not enthusiastic in learning language especially writing.