About GMA

For most organizations, people make a big difference. Studies of workplace productivity show that generally about 16% of people in any job fall into the "superior" category, with around 16% in the "poor" performer category - the vast majority of people are "average" performers.

Of most significance is the value of superior performers to an organization in terms of employee productivity. For entry level positions, superior performers can provide productivity boosts of almost 40% over "poor" performers, while for managerial roles, a 90% increase is possible. It's clear that hiring more people who are superior performers can result in very impressive gains in employee productivity.

The case for using GMA tests

GMA tests have been conclusively proven over many years to be amongst the best methods of identifying people who will be superior performers. The cost of using GMA tests is offset many times over by the gains in productivity, and organizations can save administrative time and money by only interviewing and further evaluating people who are likely to become superior performers.

Validity is the key consideration in looking at the relationship between performance on a GMA test and performance on the job. In validity studies, GMA test scores are shown to be strongly correlated with job performance variables such as sales records, substantiating the value of GMA tests in identifying superior performers.

The table below - drawn from the largest analysis ever undertaken on the role of different methodologies in staff selection*- details the validities of various assessment methods for predicting job performance represented by the validity coefficients which range in absolute value from 0 to 1.00. The higher the correlation coefficient - the more predictive the method.


Assessment Method Validity of Method
Work sample tests .54
GMA tests .51
Structured interviews .51
Job knowledge tests .48
Accomplishment record .45
Integrity/honesty tests .41
Unstructured interviews .38
Assessment centers .37
Personality questionnaires .31
Reference checking .26
Years of job experience .18
Years of education .10
Interests .10
Work sample tests are the best predictors of future job performance, followed closely by GMA assessments.

Work sample tests are typically very costly to develop and run for multiple job roles in an organization. In contrast, some GMA tests (such as those designed by ebilities) are easy to implement online and are highly cost effective.

Using a GMA test combined with other methods such as structured interviews increases validity and is the best means of quickly identifying superior performers.

For multinational organizations involved in testing people across languages, countries and cultures, it is important to ensure their tests of GMA are not only reliable and valid, but also culturally fair.


* Table adapted from Schmidt & Hunter (1998). The validity and utility of selection methods in personnel psychology: Practical and theoretical implications of 85 years of research findings. Psychological Bulletin, 124, 262-274.