Validating ESL Speaking Instrument for Vocational College Students: An Exploratory Factor Analysis
Table 5: Rules of Thumb of Cronbach’s Alpha (George & Mallery, 2003)
| Alpha Value | Level |
| >0.90 | Excellent |
| 0.80-0.90 | Good |
| 0.70-0.80 | Acceptable |
| 0.60-0.70 | Questionable |
| 0.50-0.60 | Poor |
| <0.50 | Unacceptable |