Scale

The number of observation variable

Cronbach’s Alpha

Before testing

After testing

Observation variable was removed

1. TC

4

3

1

0.930

2. DK

5

5

None

0.916

3.TL

7

7

None

0.943

4. DT

4

4

None

0.906

5. CT

5

5

None

0.923

6. DN

4

4

None

0.904

Total

29

28

1