The description, table and the figure presented above clearly represent the statistical data of students’ critical thinking ability in SMA Kharisma Bangsa. It
describes the mean, median, range and the mode score, as well as the standard deviation and variance coefficient score.
2. The Comprehension Reading Skill Data
The comprehension reading ability of students of SMA Kharisma Bangsa is determined by the test of reading comprehension that is conducted directly after
critical thinking test.
Table 4.2
The Descriptive Statistic of Comprehension Reading Data of Rater
Descriptive Statistics Rater
Mean 76.2
Median 76.0
Mode 82.0
Maximum 89.0
Minimum 64.0
Descriptive Statistic Rater
Range 25.0
Standard Deviation 5.9597
Variance 35.518
Skewness .126
Standard Error of Skewness ,398
Kurtosis -,454
Standard Error of Kurtosis ,778
Sum 2667,0
Based on the table 4.2 represented above, it shows the central tendency of reading comprehension ability. It indicates that the score appears the most mode
score is 82.0; while, the mode score given by the second rater is 73.0. Next, it is
found that the middle scores median based on two raters is same which the point is 76.0. In addition, the average score mean given by the first rater is higher than
the score given by second rater which the mean is 76.20 76.00. Similarly, the maximum and the minimum score given by rater 1 are higher than the second
rater given. It shows that the maximum score is 89.0 88.0 and the minimum score is 64.0 62.0.
Figure 4.2 Final Score of Comprehension Reading Ability Test
The difference is found in the standard deviation that is 5.9597. The range score of comprehension reading data based on the rater is 25.00; while, he
variance coefficient based on the rater is 35.518. The final score of reading comprehension test is represented in the Figure
4.2 above. It reveals that the most score appears is 75.0, and it is also as the middle score median. The minimum score is 63.5 and the maximum score is
88.5. Meanwhile, the average score mean of the final score of reading comprehension is 76.0. Additionally, the histogram above describes that the
comprehension reading ability data is normally distributed.
B. Data Analysis and Testing Hyphotheses
1. Data Analysis
Before the data is analyzed, the linearity and normality distribution of the data sets the two variables critical thinking ability and comprehension reading
ability are firstly tested. The linearity test is important to know whether the data is linear or not; while, the normality distribution is tested to know the data
normality. Furthermore, the linearity and normality tests are crucial to decide whether parameter statistic or non-parameter statistic used in this study. In this
study, the parameter statistic is used to calculate the data. Therefore, as the requirement in the parameter statistic in correlation research, the linearity and
normality of the data has to be examined first. The explanation of test of linearity and normality distribution are
presented as follow:
a. Analysis of Linearity
The linearity of critical thinking ability and comprehension reading ability data are analyzed using SPSS software. The result of the analysis is represented
in the table below:
Table 4.3 Table ANOVA
Sum of Squares
df Mean
Square F
Sig.
Comprehension Reading
Betwee Groups
Combined
783,054 14 55,932 2,581 ,026
Linearity
398,963 1 398,963 18,413 ,000
Skill Critical Thinking Skill
Deviation from
Linearity
384,091 13 29,545 1,364 ,259
Within Groups 433,346 20 21,667
Total 1216,40 34
