p = The proportion of the students who give answer the item 1
q = 1-p
= Sum of p time q S
2
= Variance of the total score
The criteria of reliability test were :
0.80-1.000 = Very high reliability
0.60-0.799 = High reliability
0.40-0.599 = Medium reliability
0.20-0.399 = Low reliability
0.00-0.199 = Very low reliability.
62
From the criteria of reliability above, it can be drawn a conclusion that the result of reliability for pre-test has a high reliability since it amounts to 0.77 and the result of
reliability for post-test has a very high reliability because it amounts to 0.82. It means that reliability of the test in the research are reliable. See Appendices 7 and 8
J. Data Analysis
1. Normality Test
The writer used normality test to know whether the data have a normal distribution or not. Here, the test of
Lilliefors
was used. When the data has been collected, so the normality test is as follows :
a. The hypothesis for the normality test is formula as follows:
62
Ibid.
p. 184.
H
o
: the data are normally distributed H
a
: the data are not normally distributed b.
The test of hypothesis is follows : 1
Arrange the data samples from the lowest to the highest 2
Determine the score of Z from each data by using the following formula Z =
̅
each of ̅ is the average and standard deviation of samples
3 Determine the probability of each Z score with
f
Z by using: If Z 0, then
f
Z = 0,5 + table score If Z 0, then
f
Z = 0,5 - table score 4
Count the cumulative frequency of each Z score SZ 5
Determine the L
o
score with the highest score, compare to the L
t
score from the table of
Lilliefors
. c.
The criteria are as follows : H
is accepted if L
observed
≤ L
critica l
, it means that the distribution or the data and normally distributed.
H is refused if L
observed
≥ L
critical
, it means that the distribution of the data and not normally distributed.
63
2. Homogenity Test
This test intends to test whether the variance of the data in the experimental class and in the control class is equal or not.
63
Sudjana,
Metode Statistika
Tarsito: Bandung, 2005. p. 467
