Measurement property | Rating | Threshold for acceptability |
---|---|---|
Internal consistency: overall scale | + | Cronbach alpha >.70 and < .95 |
 | – | Cronbach alpha <.70 and > .95 |
Internal consistency: sub-scales | + | Cronbach alpha >.70 and < .95 |
 | – | Cronbach alpha <.70 and > .95 |
Reliability | + | Intraclass Correlation Coefficient (ICC) > .70 OR Pearson’s Correlation Coefficient (r) > .80 |
 | – | ICC < .70 OR r < .80 |
Content validity | + | Assessed in target population that items are a complete representation of concept under measurement and that all items are relevant |
 | – | Questionnaire is incomplete OR contains irrelevant items |
Structural validity | + | Factors explain 50% of variance |
 | – | Factors explain less than 50% of variance |
Cross-cultural validity | + | Original factor structure confirmed OR no differential item functioning |
 | – | Original factor structure not confirmed OR important differential item functioning observed |