Validity and Reliability of Pretest and Posttest
B. Validity and Reliability of Pretest and Posttest
1. Validity of test
In this study, the researcher calculated validity of pretest and posttest using Pearson Product Moment Correlation Test.
Table 4.17
Pearson Product Moment Correlation of Pre-test in Experimental
Group
CODE
Rater I
Rater II
2 (N) 2 (X) (Y) XY X Y
E1 17 17 289
289 289
E2 30 36 1080
900 1296
E3 14 34 476
196 1156
E4 21 36 756
441 1296
E5 14 25 350
196 625
E6 14 25 350
196 625
E7 26 46 1196
676 2116
E8 29 46 1334
841 2116
729 1225 E10
E9 27 35 945
324 2116 E11
18 46 828
3364 4624 E12
58 68 3944
6561 5041 E13
81 71 5751
576 1156 E14
24 34 816
324 1156 E15
18 34 612
324 1156 E16
18 34 612
2401 2500 E17
49 50 2450
16 16 256
256 256
∑N=35 ∑X=978 ∑Y=1361 ∑XY=46755 ∑X2=39722 ∑Y2=61257
Based on the result, it find that the value of “r xy ” was0.858 than value of “r table ” at the 1% significance level or 0.858> 0.575. It means the test was valid and include at level of very high validity.
Table 4.18
Pearson Product Moment Correlation of Pre-test in Control Group CODE Rater I
∑X=71 ∑Y=90 ∑XY=2591 ∑X2=2140 ∑N=26
0 7 6 0 ∑Y2=33399
0.610
Based on the result, it find that the value of “r xy ” was0.610 than value of “r table ” at the 1% significance level or 0.610> 0.575. It means
the test was valid and include at level of high validity.
Table 4.19
Pearson Product Moment Correlation of Post-test in Experiment Group CODE Rater I
Rater II
2 (N) 2 (X) (Y) XY X Y
E1 64 71 4544
4096 5041
E2 73 71 5183
5329 5041
E3 73 71 5183
5329 5041
E4 75 79 5925
5625 6241
E5 86 81 6966
7396 6561
E6 86 81 6966
7396 6561
E7 56 81 4536
3136 6561
E8 76 81 6156
5776 6561
6561 6400 E10
E9 81 80 6480
5625 6241 E11
75 79 5925
76 81 6156
5776 6561
∑N=35 ∑X=2761 ∑Y=2794 ∑XY=220705 ∑X2=219567 ∑Y2=223336
0.41361 = 0.414Based on the result, it find that the value of “r xy ” was 0.414It
means the test was valid and include at level of fair validity.
Table 4.20
Pearson Product Moment Correlation of Post-test in Control Group
Rater I
Rater II
2 CODE (N) 2 (X) (Y) XY X Y
∑N=26 ∑X=1576 ∑Y=1339 ∑XY=83917 ∑X2=101492 ∑Y2=72907
Based on the result, it find that the value of “r xy ” was0.567 It means the test was valid and include at level of fair validity.
2. Reliability of Test Table 4.21 The Item-Total Statistics of Pretest in Experiment
Item-Total Statistics
Scale Mean if Scale Variance Corrected Item- Cronbach's
Item Deleted
if Item Deleted
Total
Alpha if Item
Deleted Cont
The Reliability Statistic of Pretest in Experiment
Reliability Statistics
Cronbach's
N of Items
Alpha
The result of r 11 = 0.902 with 7 items and r table of Product Moment is df= N- 1; 35 – 2 = 33, the level of significant 1%, so r table = 0.575. Clearly at the criteria :
If r 11 >r table it means reliable If r 11 <r table it means unreliable Based on the calculating above, the result is if r 11 = 0.902> r table = 0.575, it concludes that the first item (Pretest) is reliable.
Table 4.23
The Item-Total Statistics of Pretest in Control class
Item-Total Statistics
Scale Mean if Scale Variance Corrected Item- Cronbach's
Item Deleted
if Item Deleted
Total
Alpha if Item
Deleted cont
The Reliability Statistic of Pretest in Control class
Reliability Statistics
Cronbach's
N of Items
Alpha
The result of r 11 = 0.826 with 7 items and r table of Product Moment is df= N- 1; 26 – 2 = 24, the level of significant 1%, so r table = 0.575. Clearly at the criteria :
If r 11 >r table it means reliable If r 11 <r table it means unreliable
Based on the calculating above, the result is if r 11 = 0.826> r table = 0.575, it concludes that the first item (Pretest) is reliable.
Table 4.25
The Item-Total Statistics of Post test in Experiment class
Item-Total Statistics
Scale Mean if Scale Variance Corrected Item- Cronbach's
Item Deleted
if Item Deleted
Total Alpha if Item Correlation
Deleted cont
The Reliability Statistic of Post test in Experiment class
Reliability Statistics
Cronbach's
N of Items
Alpha
The result of r 11 = 0.581 with 7 items and r table of Product Moment is df= N- 1; 35 – 2 = 33, the level of significant 1%, so r table = 0.575. Clearly at the criteria :
If r 11 >r table it means reliable If r 11 <r table it means unreliable Based on the calculating above, the result is if r 11 = 0.581> r table = 0.575, it concludes that the first item (Pretest) is reliable.
Table 4.27
The Item-Total Statistics of Post test in control class
Item-Total Statistics
Scale Mean if Scale Variance Corrected Item- Cronbach's
Item Deleted
if Item Deleted
Total
Alpha if Item
Deleted Cont
The Reliability Statistic of Post test in control class
Reliability Statistics
Cronbach's
N of Items
Alpha
The result of r 11 = 0.837 with 7 items and r table of Product Moment is df= N- 1; 26 – 2 = 24, the level of significant 1%, so r table = 0.575. Clearly at the criteria :