Without exaggeration I hear clients, prospects, and even consultants lump DISC and personality tests together every day when discussing pre employment tests. In some respects that is like comparing apples to oranges, peaches to bananas and so on. In other words, there are literally thousands of tests available measuring attitudes, interest, motivation, intelligence, skills, behavior and personality. Many of these appear quite similar on the surface and everyone one of them claims to be predictive. But behind every report there is an important story.

With so many assessment options available, what’s a manager to do?

This post focuses on a few qualifications every manager and HR professional should be asking assessment providers.

You might be thinking – here he goes again: more about that validity gibberish. So let’s get that out of the way. This column is not about validity and reliability. Those criteria are a given in the world of psychometrics. This post is about two terms you likely never heard of.

The broad description of “personality tests” fall into two distinct types – ipsative and normative. It is essential that an organization understands the differences between these test types because both types can pass the validity and reliability litmus test. Not knowing whether the construct of the assessment is ipsative or normative can be risky business for a business that wants to ensure predictability for future job performance and defensibility if ever challenged.

DISC assessments are considered ipsative tests. Like the hundreds of other assessments based on the four style behavioral model, DISC reports the relative strengths of the person being tested. For instance, D represents “direct” or “dominance” and S represents “steady.” If a DISC assessment reports the individual is “high D” and “low S,” this merely means this individual is more energized by asserting him/herself in dealing with problems than maintaining a steady pace. What it does not reliably predict is how two people with similar DISC patterns will perform a job or interact with others. Just because an individual describes himself as direct, does not mean he will be effective at asserting himself or making decisions. It is also not an accurate predictor of how much more or less assertive he might be compared to other “high D”

The reason for this ambiguity is that ipsative literally means “of the self” and therefore have extremely high face validity – when a test-taker reads his report, he agrees it is very accurate at describing his approach to people and tasks. Ipsative tests therefore indicate how one individual prefers to respond to problems, people, work pace and procedures. It however offers little correlation at comparative strength of relationship skills or task completion between one person and another.

Ipsative tests are very effective when used for developmental, coaching, team building and interpersonal conflict resolution. On the other hand, ipsative types of test should not normally be used in recruitment and selection as the exclusive assessment and should never be used to predict performance or job fit.

Normative tests, unlike ipsative tests, measure quantifiable personality characteristics on individual scales. An individual’s “score” measures a specific characteristic against confirmed patterns of normality, usually represented as a bell curve. Normative testing allows people to be compared to particular groups and populations. In business, normative testing allows individuals to be compared to other employees who have met with success or failure in a job. The hope for managers using normative tests is that they can predict candidates who will have the best chances of success if hired or promoted and to avoid placing the wrong employee in the wrong position. Normative tests are therefore best suited as a recruitment and selection instrument but are also useful in developmental, coaching and training.

Normative testing generally has a higher validity than ipsative. Depending on the instrument used the predictive or criterion validity can be 70 percent or higher depending on the assessment and the job..

Success Performance Solutions offers both ipsative and normative testing. DISC and Business Values and Motivators are considered ipsative while Prevue, ASSESS, and Clues are normative.