45
35 items of try out test, there was 13 items were easy, 17 items were medium and 5 items were difficult.
4.1.3.2 The Discriminating Power
The discrimination index of an item indicated the extent to which the item discriminated between the testers, separating the more able testers from the less
able. The index of discriminating told us whether those students who performed well on the whole test tended to do well or badly on each item in the test. There
were four categories of the discrimination index, they are: excellent, good, satisfactory, and poor.
Based on the analysis of validity, reliability, difficulty level and discriminating power, finally 30 items were accepted from 35 items of try-out test
were used as instrument to make the scoring easy. The test items which did not fulfill the requirements of the valid test were invalid and they had to be rejected.
Items numbers 6, 8, 17, 24, and 28 had to be rejected.
4.2 Data of the Pretest and the Posttest
Before the experiment was conducted, the students were given a pretest. The test was a writing test. After the treatments, I gave the posttest. The scores of the
pretest and the posttest were obtained from 30 multiple choice items.
4.2.1 Pre-test Finding
Pre-test was the test that was held before giving the treatments in order to find out the prior knowledge or ability or skill of the test takers before the
treatments were given. In this case, the purpose of giving pre-test was to investigate the students’ ability in reading. The pre-test was conducted on
46
November 29, 2010.There were 30 students for experimental group, VIII E and
30 students for control group, VIII D participating on the pre-test. The result of the pre-test can be seen in appendix 11.
The writer analyzed the pre-test which was conducted to both classes. The pre-test showed the prior knowledge of the
students in both experimental group and control group. 4.2.1.1 Pre-Test Analysis of the Experimental Group
The writer conducted the pre-test at this same day for both classes. The aim of conducting a pre-test was to know the prior knowledge of the experimental
group students. The writer took class VIII E as the experimental group. The class consisted of 30 students.
The mean of the pre-test for the experimental group students was as follows:
∑
Where: : The mean of pre-test score for experimental group students
∑ : The sum of pre-test score for experimental group students
: The number of experimental group students The computation was as follows:
, From that computation, the mean pre-test score for experimental group students in
doing the pre test was 62, 67.
47
4.2.1.2 Pre-test Analysis of the Control Group The writer used two classes in her study because she wanted to compare the
significant difference achievement between the experimental and control group. The writer took class VIII D as he control group. The mean of the pre-test for the
control group students was as follows: ∑
Where: : The mean of pre-test score for control group students
∑ : The sum of pre-test score for control group students
: The number of control group students The computation was as follows:
, From that computation, the mean pre-test score for control group students in
doing the pre test was 60, 53. T he students’ average score of pre-test was
analyzed. The average score of the pre-test between the experimental group was 62, 67 and the control group was 60, 53
.
It meant that the students’ achievement of the experimental and control group was relatively same before the treatments
were given.
a I
4
t
n
4
V t
t e
The r achievement
It could be s
4.2.2 Trea
Kategori