Evidence of 12-year predictive and concurrent validity for SII Occupational Scale scores

This longitudinal study assessed the power of the Occupational Scales (OSs) of the Strong Interest Inventory to predict the participants’ occupations 12 years after Time 1 testing, 8 years after Time 2 testing, and concurrently at Time 3. Results indicated that OS scores predicted occupational membership at a level substantially higher than chance at all three points in time. Eight-year and concurrent prediction hit rates were not significantly different from each other but were significantly higher than 12-year hit rates. No significant gender differences were found, and OSs predicted membership equally well for occupations that corresponded directly to those represented on the SII profile and occupations indirectly represented on the inventory. These findings are important for informing counseling practice and providing validity evidence for SII scale scores.