A priori hypotheses for construct validity
| Type of construct validity (subtype) | Hypothesis |
| Between-PROM (convergent validity) | Correlations with instruments measuring similar constructs should be ≥0.50 |
| Between-PROM (convergent/divergent validity) | Correlations with instruments measuring related, but dissimilar constructs should be ≥0.30 |
| Between-PROM (divergent validity) | Correlations with instruments measuring unrelated constructs should be <0.30 |
| Within-PROM (convergent validity) | Correlations between an item and its own scale (corrected for overlap) should be ≥0.40 |
| Within-PROM (divergent validity) | Correlation between an item and its hypothesised subscale (corrected for overlap) is higher than its correlation with the other subscales |
PROM, patient-reported outcome measure.