Why communication and behavourial assessment like DISC can’t predict sales performance

It is a misconception that certain types of assessment are tools for selecting candidates for sale or measuring world-class performance. Assessments come in two forms: they are either 'ipsative' or 'normative'.

Ipsative assessments measure a person's perception of themselves. They are an excellent tool for improving self-awareness, team building, communication, and coaching or counselling. The disadvantage is that there are no measurement standards, so you cannot use them to compare two people or, in our case, two sales candidates. You also cannot perform predictive validation, as this requires a standard measurement.

Imagine a survey in which you ask a 3-year-old, a 10-year-old and a 20-year-old if they are tall... and they all answer yes.

This is self-perception, and on paper, they all appear to be equally tall. The best-known ipsative assessments are: DISC, MBTI, P3, PF16, Insights, TTI, Innermetrix and Predictive Index, to name but a few.

Another disadvantage is that if you use an ipsative test for hiring and the candidate sues the employer, the test cannot be defended. It is the employer who is liable, not the assessment company.

Let's be clear. I am a strong user of DISC reports. Self-awareness is key to personal development. And DISC is useful for developing better relationships with our prospects and colleagues. I constantly think about my own profile and how I can improve these aspects of communication and behaviour.

Normative assessments have a standard of measurement and are used to compare different people or things to that standard. A typing test measuring words per minute, a blood test measuring cholesterol levels, a maths test at school and the results obtained in comparison to other students—all of these tests have a standard of measurement. When you use a normative test, construct it correctly, and test it on a sufficiently large sample population, you can determine predictive validity. This is a long and costly process and the highest form of validation.

In the case of OMG, this means that you can select sales candidates and, in 91% of cases, be correct about their ability to perform or not perform in sales.

If you want to compare sales candidates or make your current sales team the best in the industry or world-class, you need normative data. To my knowledge, the only sales assessment that has normative data and predictive validation is OMG. What's more, the technical manual is available, as are third-party audits conducted to validate the level of prediction.