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4.2.1.1 Item Validity
Validity refers to the extent to which inferences made from assessment results are appropriate, meaningful, and useful in terms of the purpose of the assessment. In
the computation of item validity in pre-test, the validity index of number 22 is 0.66. Then I consulted the table of r with N = 36 and significance level = 5
is 0.338788. Since the result of the computation is higher than r in the table, the index validity of item number 22 is considered to be valid. While in the
computation of item validity in post-test, the validity index of number 3 is 0.81. Since the result of the computation is higher than r in the table, the index validity
of item number 1 is considered to be valid. See in Appendix Based on the computation of all items, there was no item which is invalid
on the try-out test for pre-test in the other word, all items are valid. On the other hand, there was 1 item which is invalid in the try out test for post-test. It is the
item number 11. Therefore, the other items would be used in the test. Since there were 29 valid items, I used 25 items for the pre-test and post-test based on the
consideration of level of difficulty and the aspects of reading comprehension.
4.2.1.2 Reliability
Similar to validity, reliability is also the characteristics of a good test. Reliability is meant the stability of test scores. A reliable test is consistent and dependable. If
the test is given to the same students on two different occasions, the test will show similar results. The reliability of the test was calculated from the number of
items, the means of scores, and the total of variants. A test is considered to be
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reliable if r
11
result of calculation is higher than r in the table 0.338788. From the calculation for significance level 5 and the number of students is 36, the
result was 0.96. Since the r
11
is higher than r
table
, the test was considered to be reliable. Meanwhile, in the try out of post-test, the result was 0.95. Therefore, it is
also considered to be reliable.
4.2.1.3 Level of Difficulty
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