Technique of Collecting Data

the interview to the teacher before and after Classroom Action Research CAR and in analyzing quantitative data, the writer uses the tests pretest, posttest 1, and posttest 2. In analyzing numerical data, the writer finds out the average of students’ reading score per action within one cycle. She uses this formula: 5 It is caused that she needs to analyze the data by getting the average of students’ score. X = Mean ∑x = Individual score n = Number of students Next, the writer wants to get the class percentage which passes KKM 65 sixty five of English lesson at MTsN 19 Pinang Kalijati. She needs the class percentage to know how many percent that students’ score and she uses this formula: 6 P : The class percentage F : Total percentage score N : Number of students The last, after getting mean of students’ score per actions, the writer analyzes students’ reading score from pretest up to posttest in cycle 1 and cycle 2. It used to know whether students improve their score or not. She uses the formula: 7 5 Sudjana, Metoda Statistika, Bandung: PT. Tarsito, 2002, p. 67. 6 Anas Sudijono, Pengantar Statistika Pendidikan, Jakarta: PT. Raja Grafindo Persada, 2008, p.43 77 David E. Meltzer, The Relationship between Mathematics Preparation and Conceptual Learning Gains in Physics: A Possible Hidden Variable in Diagnostic Pretest Scores, Iowa: Department of Physics and Astronomy, 2008, p.3. _ ∑x X = ── n F P = ── X 100 N P : Percentage of students’ improvement y : Pre-test result y1 : Post-test 1 P : Percentage of students’ improvement y : Pre-test result y2 : Post-test 2

I. Validity of Data

The writer uses validity of the tests to ensure that the research can be acceptable. In analyzing the data, the writer makes the trustworthiness of study which consists of discriminating power and item difficulty. 8 First, the writer analyzes discriminating power by dividing students into two groups. Those are upper group and lower group. Second, because there are forty students in the class, she only chooses ten students from the upper group and lower group to know the discriminating power. Then, she analyzes the students’ answer on pretest, posttest 1, and posttest 2. From the result, she knows whether good or bad of discrimination power. Next, she analyzes item difficulty to know how many students select the correct answer. From the result, she knows whether high or low of difficulty item. Finally, she can get the validity by matching the result of discriminating power and difficulty item. 8 See appendix, p. 95. y1 - y P = ─── X 100 y y2 - y P = ─── X 100 y