Adverse Impact
Another concept that is critical to understand in order to evaluate assessment methods
is adverse impact. Adverse impact can occur against protected demographic groups,
such as African Americans, Hispanics, females and individuals over 40, when certain
types of assessment methods are used for selection. Adverse impact results in a disproportionately
small number of individuals in a protected group versus the majority
group being selected for a job. For example, adverse impact against females is observed
frequently when physical ability tests that measure upper body strength are used for
selection in physically demanding jobs. Other types of assessments (e.g., tests of general
cognitive ability), likewise, tend to systematically produce adverse impact against
minority groups.
Adverse impact is examined by comparing the proportion of majority group members
who are selected for a job to the proportion of protected group members who are
selected. Continuing with the example of males versus females being assessed for their
upper body strength, suppose that 50 females and 50 males are examined. Further
assume that 35 females pass the assessment and are selected, and 45 males pass the
assessment and are selected.
The proportion of females passing the test is 30/50 or 60%.
The proportion of males passing the test is 45/50 or 90%.
The proportion of females passing the test compared with males passing the test is
60%/90% or 67%.
Adverse impact exists if the proportion of protected group members selected is less
than 80% of the proportion of majority group members selected. In this case, because
the ratio of females selected to males selected is only 67%, it can be concluded that the
test is producing an adverse impact against females.
While organizations are and should be interested in selecting the highest quality workforce
possible, many are also concerned about selecting a diverse workforce and not