Questionnaire Research Instruments and Data Gathering Technique

39 mean scores. The mean scores were calculated from the scores of 19 students as the participants N=19. The range of the score from each category was 1-4; the lowest score was 1, the highest score was 4. The range of the score from the total raw mean score was 4-20; the lowest score was 4, the highest score was 20. The range of the final mean score was 20-100, which was the converted raw scores into the scale of 0-100; the lowest score was 20, the highest score was 100. The results of the mean scores were presented in form of tabulation, as presented in table 3.2. 2. Percentage difference Percentage difference is a descriptive statistics which compares two numerical data to see the associations between two of them Cohen, Manion, and Morrison, 2011. According to Cohen, Manion, and Morrison 2011: The percentage difference is a simple asymmetric measure of association. An asymmetric measure is a measure of one-way association. That is to say, it estimates the extent to which one phenomenon implies the other but not vice versa p.631 Below is the formula of percentage difference: PD = Percentage difference X2 = Cycle 2 mean score X1 = Cycle 1 mean score Scale = Data scale Figure 3: Formula of percentage difference 40 Each mean score were calculated into percentage based on each scale 0-4 for the five categories of critical writing, 0-20 for the raw score, and 0-100 for the final score. The mean scores from each meeting in cycle 1 and cycle 2 were compared to get the percentage difference as the change percentage from cycle 1 to cycle 2. After that, the change percentage was described and interpreted as the result of the implementation of collaborative learning in improving students’ critical thinking skills in CRW II; positive percentage meant increasing scores and positive improvement, zero percentage meant stagnant scores and non improvement, and negative percentage meant decreasing scores and negative improvement. The results of the percentage differences were presented in form of tabulation, as presented in table 3.2. Table 3: Tabulation of mean scores and percentage differences NO. CRITERIA MEAN SCORE CHANGE IN C R EA S IN G D EC R E A SI N G CYCLE 1 CYCLE 2 1 Arguments Scale = 0-4 X1 X2 PD 2 Evidences Scale = 0-4 X1 X2 PD 3 Target Audience Scale = 0-4 X1 X2 PD 4 Organization Scale = 0-4 X1 X2 PD 5 Sources Scale = 0-4 X1 X2 PD 6 Total Raw Mean Score Scale = 0-20 X1 X2 PD 7 Final Mean Score Scale = 0-100 X1 X2 PD PLAGIAT MERUPAKAN TINDAKAN TIDAK TERPUJI