| Category | Cronbach’s Alpha is based on standardized items | Number of items |
| I | Excellent | [0.9 - 0.8] |
| II | Good | [0.8 - 0.7] |
| III | Medium | [0.7 - 0.6] |
| IV | Qualified | [0.6 - 0.8] |
| V | Unqualified | [0.5 - 0.0] |