BA BB JA
JB 4 Divided the difference by the number of the students in one group.
The discriminating power measured how well the test items arranged to identify the differences in the students’ competence. After the trial test was carried
out, an analysis was made to find out the discriminating power of each item. The formula of calculating the D was:
D =
In which, D
: discriminating power BA
: number of students in the upper group who answered the item correctly BB
: number of students in the lower group who answered the item correctly JA
: number of all students in the upper group JB
: number of all students in the lower group Arikunto, 2006:208
In order to know the level of the Discriminating Power of each items, the writer consulted score D that will be gained from the computation. The
Discriminating Power classification is as follow: 0.00 D
0.20 = poor 0.21 D
0.40 = satisfactory 0.41 D
0.70 = good 0.71 D
1.00 = excellent Arikunto, 2006:208
If the D is negative, all of the items are not good. So if all items which have value are negative, it will be better to throw them away.
The complete result of the computation of the Discriminating Power of the try out test can be seen in
appendix 4.
3.5.1.4 Difficulty Level of the Test
Arikunto 2006:209 states that difficulty level is a number that shows the case and difficulties of an item. A good test is a test which is not too easy and difficult.
To compute the difficulty level of the test, this research used the following formula:
P= In which:
P = the difficulty level B = the number of the students who answered the item correctly
JS = the number of the students in a class Arikunto 2006:210 classifies the difficulty level of an item as follows:
1 Item with P 0.00 – 0.30 is a difficult item 2 Item with P 0.31 – 0.70 is a medium item
3 Item with P 0.71 – 1.00 is an easy item.
3.5.2 Pre-test
The pre-test was administered before an experiment or a treatment given. The pretest in this study had a purpose to know the students’ basic ability on reading
achievement. It was given to both the control and experimental groups. Before taking the pretest, students were not taught the material as the basic knowledge.
The pretest was conducted on Tuesday, May 14
th
2012 for control group and on Wednesday, May 15
th
2013 for experimental group. The students were asked to do the test consisting of 25 multiple-choice items in 40 minutes. There were 30
students of VIII C as the experimental group and 30 students of VIII B as the control group joined the test.
3.5.3 Treatment
The teaching-learning processes of this study became the processes of giving treatment. The process of giving treatment was in order to make sure that the
semantic mapping strategy definitely gave effect to the students’ achievement in reading narrative text and to reach the main purpose of this research.
The treatment was given after the experiment and control class done the pretest. The experimental group got a treatment by using semantic mapping
strategy. On the other hand, the control group was taught by using quick reading method. The treatment was conducted for two meetings. It was because the
limited time given by the teacher and both class was explained about the narrative text and they had the material, assignment and test from their teacher. The
treatment for control class was conducted on Thursday, May 16
th
2013 and on Tuesday, May 21
st
2013. Then the treatment for experiment group was conducted on Friday, May 17
th
2013 and on Wednesday, May 22
nd
2013. There were 30 students in control group and 30 students in experimental group who joined in this
