In personnel selection, employment tests are intended to reduce selection errors and increase mean performance. The current thesis examines the impact of psychometric properties of the predictors on selection accuracy, or the consistency between selection on observed scores versus true scores. Implications for validity and subsequent levels of job performance, or prediction accuracy, are also examined in light of common top-down personnel selection procedures. Results reflect the importance of having reliable and valid predictor measures; the work also extends ideas in the area of utility analysis.