35 Meanwhile, the external validity of the instruments in this study is reached
by correlating the results of try-out with the students’ English scores they gained in the first semester. Here, the statistical analysis of Pearson Product Moment
Correlation coefficient is used Evelyn, 1991:434 to analyze the data. The value of the correlation coefficient was obtained calculated by using SPSS Statistical
Package for Social Sciences. The computation shows the result is .882 for the test, which means that the
test is valid since r table with .01 and df = 28 is .4487 Appendix 10.
3.3.2 Reliability of the Test
The reliability of the test items also was calculated by using SPSS by stating the total of odd score and even sore of the items. From the calculation, it is
shown that the reliability index is .666 for the test, while r table with df= 28 and = 0.01 is .4487 Appendix 11. It means that the r of the test is greater than that of
the table. Thus, the test items can be said to be reliable.
3.3.3 Test Items Difficulty
The indexes of items difficulty are calculated using the analyses of test item ANATES Version 4.0.2. The analysis show that from 50 items for the test,
after being tried out, only 48 which can be used, consisting of 4 difficult items, 32 medium items, and 12 easy items Appendix 6. The rest 1 is too easy and 1 is too
difficult, so that they were eliminated from the test. To make the scoring easier, only 40 items for test were chosen.
36
3.3.4 Test Items Discriminating Power
The indexes of items discriminating power are also calculated using the analysis of test item ANATES Version 4.0.2. From the analysis, it can be seen
that from 50 items for the test, 1 item has very good discriminating power , 10 items are good, 29 items are medium, 6 items are bad, and 4 are very bad
Appendix 5. So, of all, there are only 40 items can be chosen. Having analyzed the try out result, 40 items were selected for the test. The
items selected are those which have level difficulty range from easy, medium and difficult and level of discriminating power range from 12.50 to 75.00 with
distracter quality level of good and very good Appendix 7. The characteristics of the selected items for the reading test are in the following table:
Table 3.2 The Characteristics of the Selected Items of Reading Test
Question Item Difficulty
Discrimination Power Distracter Quality
1 2
3 4
5 6
7 8
9 10
11 12
13 Medium
Easy Difficult
Medium Easy
Medium Medium
Medium Medium
Easy Easy
Medium Medium
25.00 37.50
62.50 50.00
37.50 25.00
12.50 37.50
12.50 37.50
25.00 75.00
50.00 Very Good
Good and Very Good Good and Very Good
Good and Very Good Good and Very Good
Good and Very Good Good and Very Good
Good and Very Good Good and Very Good
Good and Very Good Good
Good and Very Good Very Good
37 14
15 16
17 18
19 20
21 22
23 24
25 26
27 28
29 30
31 32
33 34
35 36
37 38
39 40
Medium Medium
Difficult Medium
Easy Easy
Easy Easy
Difficult Medium
Easy Medium
Easy Medium
Medium Medium
Easy Medium
Medium Medium
Medium Medium
Medium Medium
Medium Medium
Medium 50.00
37.50 25.00
12.50 25.00
50.00 25.00
37.50 62.50
12.50 25.00
37.50 25.00
37.50 37.50
62.50 25.00
25.00 25.00
37.50 50.00
37.50 50.00
37.50 37.50
25.00 25.00
Good and Very Good Good and Very Good
Good and Very Good Good and Very Good
Good and Very Good Good and Very Good
Good and Very Good Good and Very Good
Good and Very Good Good and Very Good
Good and Very Good Good and Very Good
Good Good and Very Good
Very Good Very Good
Good and Very Good Very Good
Good and Very Good Good and Very Good
Good and Very Good Good and Very Good
Very Good Very Good
Very Good Good and Very Good
Good and Very Good
38 From the table of the characteristics of the selected items for the reading
test above can be seen that for the level of difficulty, there were 11 easy items, 26 medium items, and 3 difficult items. For the discriminating power, there were 4
items in the range of 12.50, 13 items in the range of 25.00, 13 items in the range of 37.50, 6 items in the range of 50.00, 3 items in the range of 62.50, and 1 item in
the range of 75.00. While for the distracter quality, there were 2 items in the level of good, 8 items in the level of very good, and 30 items in the level of good and
very good.
3.4 Variables and Hypothesis
