call (214) 613-3983
mail Contact Us
🇭🇰 English (UK)
passkey Sign in
30
years

Professional DISC assessment solutions since 1994

DISC Testing: Reliability and Validity

Measuring the effectiveness of DISC

Reliability and Validity are two concepts that help to quantify the performance of any profiling tool.

Probably the most important question about about any personality test is: how well does it measure what it claims to measure? To be of any practical use, you need confidence that profiles accurately represent the actual personalities they describe.

There are two important statistical values that help to measure this level of effectiveness, known as reliability and validity. We'll take a moment here to see what each of these measures means in practice, before going on to see how they relate to DISC testing.

Reliability

The first measure is a question of consistency: if we test the same person several times, we'd expect to get similar results each time. Reliability measures how much profile results change from one test to another (actually, we should mention that there are several different types of reliability, and the form we're discussing here is specifically test-retest reliability).

We'd certainly not expect results to vary wildly from profile to profile over time, so for an effective profile, we're looking for a high reliability score. Note, though, that people's attitudes and approach really do change over time, so we wouldn't expect to see a 100% reliability level from one profile to the next. (Indeed, understanding changes like this can be valuable in assessing a person's actual performance.)

Validity

A more difficult challenge is assessing the validity of a set of profile results: that is, do the factors in a profile measure the personality traits they describe. The usual approach in this context is to measure profiles against another well-established personality inventory. The preferred comparison in a case like this is Cattell's Sixteen Personality Factor questionnaire (or 16-PF for short).

Different profiling techniques measure different factors, so we wouldn't expect to find exact matches in the comparison. We can, however, look at correlations between factors in the two systems, to establish whether factors in one test demonstrate a consistent statistical relationship with those in the other.

DISC Assessed: The Roodt Report

The Roodt Report: Reliability and Validity

You can find a full analysis of how DISC measures up in terms of validity and reliability in A Reliability and Validity Study on the Discus Personality Profiling System. This independently-produced paper is known informally as the Roodt Report after its author, psychologist Karin Roodt of Technikon Natal in South Africa. You can read the full contents of the paper at the link below:

The Complete DISC Solution For Your Business

  • Reliability: A measure of how consistently a test measures a person's personality factors from one profile to the next.
  • Validity: A measure of how well a profiler reports on the specific factors it is designed to assess.
  • A Note on Scales: If you're unfamiliar with statistical reporting, it might be useful to mention that values are typically expressed on a scale from 0.0000 to 1.0000. If it's helpful, you can think about this scale as corresponding to the more familiar 0% to 100%.
  • About p-Values: The 'p-values' you'll find in the report describe the probability that a particular correlation occurred by chance, so lower values relate to more strongly established correlations. Conventionally a p-value of less than 0.0500 is seen as statistically significant.
Get Started Now

Get Started Now

Choose the package to suit you from our range of special business offers.

Looking for your own personality report?

Looking for your own personality report?

Understand your work style, help build your CV, and much more with your own personal report.

Download your <em>free</em> guide to DISC personality testing

Download your free guide to DISC personality testing

DISC: The Complete Introduction

Learn how DISC assessment can help improve your recruitment process, team building and leadership development.

Sitemap Agency Opportunities Download a Free DISC Guide
Axiom Software Ltd Head Office: Empress Buildings, 380 Chester Road, Manchester, M16 9EA, United Kingdom
Telephone: +44 (0)161 408 2112|Skype: axiom_office|E-mail
Registered in England No 02888933|VAT No UK VAT: GB638 8466 88 / EU VAT MOSS: EU372018397|Privacy Policy|Terms of Use
Copyright © 2016-2024 axiominternet group limited