A researcher runs a hierarchical regression predicting job performance. Model 1 includes experience and education: R Square = .30. Model 2 adds conscientiousness: R Square = .36. SPSS reports R Square Change = .06, F Change(1, 96) = 8.20, p = .005. What is the BEST interpretation of the effect size of adding conscientiousness?
Conscientiousness adds 6% additional explained variance in job performance beyond experience and education; this increment is statistically significant.
Conscientiousness improves job performance by 6 points on average, and the effect is statistically significant.
Because the F Change is significant, conscientiousness is the strongest predictor in the model.
R Square Change of .06 means conscientiousness explains 36% of job performance by itself.