P =
Explanation: P: Item Difficulty
B: The number of students who got the item right JS: The total number of students who tried the item
Classification of difficulty index: 0.00
– 0.19 = very difficult
0.20 – 0.39
= difficult 0.40
– 0.59 = moderate
0.60 – 0.79
= easy 0.80
– 1.00 = very easy
In analyzing the data, the researcher usedt
test
formula through SPSS Special Package of the Social Sciences version 22 software. The t-
test
is one of a number of hypothesis tests. Before calculated t-test, the researcher did normality and
homogeneity tests first.
5. Normality Test
Before the researcher calculated the value of t-test, the researcher had to analyze the normality and homogeneity of the data. He examinition of
normality was needed to know whether the data has been normally distributed. The researcher used SPSS to tets the normality. In SPSS,
there are two kind of normality test: Kolmogrov Smirnov and Shapiro-Wilk.
The criterion of SPSS: a. If respondents
≥ 50, the normality test uses Kolmograv Smirnov. b. If respondents
≤ 50, the normality uses Shapiro Wilk. The criterion of hypethesis is:
H : Significant Score 0,05
H
1
: Significant Score 0,05
6. Homogeneity Test
The next step was calculating the homogeneity of data. The purpose of this calculation was to see whether the data sample in both classes were
homogenous or heterogeneous.
7. T-Test
After getting the data from pre-test and post-testfrom experimental and controlled class, the researcher needs to find out the differences score
using crossword puzzle as media. Here, the two classes are compared to the independent variable, the experimental class is X variable and the
controlled class is Y variable. The researcher used statistical calculation of the t-testformula. It is used to know whether sudents improve their
score or not.
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The formulas as follows:
Where: Mx
= Mean of experimental group Variable X My
= Mean of control group Variable Y SEMx = Standard error of mean Variable X
SEMy = Standard error of mean Variable Y
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Budi Susetyo, Statistika Untuk Analisis Data Penelitian, Bandung: Refrika Aditama, Bandung, 2010, p. 203
