0.60 – 0.80
High 0.40
– 0.60 Enough
0.20 – 0.40
Low 0.0
– 0.20 Very low
After the calculation using “ANATEST”, the validity value or XY
correlation of the pre-test instrument used in this study was 0.69. It means the test is valid and categorized into high quality. It was gotten the data
from 40 forty questions multiple choices that was examined before and got 25 twenty- five questions that was valid through ANATES software.
Instrument that was valid are number 1, 4, 5, 7, 9, 10, 13, 16, 17, 18, 20, 21, 22, 23 24, 26, 28, 29, 31, 33, 34, 37, 38, 39, and 40. Meanwhile, the
reliability of the instrument was 0.81 which means the test is valid and categorized into very high reliability. Then, the validity value of post-test
2 used in this study was 0.55. it means the test is valid and categorized into enough quality. Then, the reliability of the instrument was 0.71 which
means the test is valid and categorized into high reliability. 2. Discrimination Power
The analysis of discrimination power test items is to know the performance of the test through distinguishing students who have high
achievement and low achievement. Item discrimination provides more detailed analysis of the test items difficulty, because it shows how the top
scores and lower scores performed on each item. The formula as following:
13
D =
D : The index of discriminating power U : The number of correct answer in the upper group
13
Sugiyono, op.cit. p. 257.
L : The number of correct answers in the lower group N : The total number of people in the top group
The discriminating power scale uses:
Table 3.2 Discriminating Scale
DP REMARK 0.6
– 1.0
Very Good
0.4 – 0.6
Good
0.1 – 0.3
Enough
-1 – 0.0
Bad
3. Item Facility Item facility difficulty item concern on the proportion of comparing
students who answer the questions correctly with all of the students following the test. Item difficulty is how easy or difficult is the test based
on the group of students. The formula as following:
14
IF = N
correct
N
total
IF : Item facility N
correct :
Number of students who selected the correct answer N
total :
Total number of students taking the test
66.
14
James Dean Brown, Testing in Language Programs, New York: McGraw-Hill, 2005, p.
The criterion that is used is as:
Table 3.3 Criterion Scale
ID REMARK – 0.14
Difficult
0.15 – 0.85
Moderate
0.86 – 1.00
Easy
H. The Criterion of the Action Success
Classroom action research CAR is able to be called successful if it can fulfill the criteria which have been determined, and fail if it cannot fulfill the
criteria which have been determined. In this study, the research will succeed when there is 75 of students achieve the Minimal Mastery Criterion KKM,
gaining score 70 seventy or above of vocabulary test started from pre-test up to the last cycle. If the criteria of the action success reached, it means that the
next action of the Classroom Action Research would be stopped, but if the criteria has not been achieved yet, the alternative action would be done in the
next cycle.
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