Early checklist-based instruments were often plagued by susceptibility to participant evasion, particularly through over-agreement or under-agreement with certain concepts. The Omnia Profile controls for this through linear transformation of participants’ scores into a T-distribution based on the mean values within the test-taking population. Furthermore, the Omnia Profile measures intensity (strength of preferred behavioral characteristics) and purpose (maturity and comfort with responses) as additional safeguards against evasion.
The predictive validity of the assessment was independently certified in 1987 and 2000. Both the internal reliability of the Omnia Profile and its predictive validity were evaluated in each study. In the 1987 evaluation, based on a sample of 381 adults, both respondents and their co-workers assigned a high degree of accuracy (83 and 89%, respectively) to the results of the Omnia Profile. Additionally, the study confirmed that Omnia Profile results were independent of race/ethnicity, gender and age. The 2000 study examined 500 Omnia Profiles and measured coefficient alpha for each construct and item on the assessment to ascertain internal reliability. Based on the study, certain words in the checklist were updated. The coefficient alpha for the new Omnia Profile was 0.95, well above the 0.80 standard recommended by the U.S. Department of Labor for employee selection assessments.
Finally, the 2000 study measured the Omnia Profile’s performance against a similar, well established psychometric instrument (The NEO Five-Factor Inventory) and against supervisor performance rating in a sample of 315 call center employees. The study found strong agreement between the Omnia Profile and the NEO-FFI, which was statistically significant in more than half of the areas measured. The coefficient alpha for correlation between the Omnia Profile and the performance ratings of the call center employees was also high (0.85), further substantiating the predictive validity of the assessment. Subsequent to 2000, analyses conducted at several Omnia clients have continued to support the validity of the Omnia Profile in predicting employee performance.