The science behind Everything DiSC®
DiSC is easy to remember, but the assessment behind Everything DiSC® is serious. It is independently certified, its reliability is published, and it adapts to each person’s answers. Here is the evidence, and the limits, in plain language.
Internal consistency, median
Research threshold: .70
Independent review
Certified by DNV
to the EFPA test-quality standard · renewed 2024
Test-retest, after two weeks
.85 to .88
8 scales, 599 people
How it asks
Adaptive: unclear answers trigger extra questions
How Everything DiSC® measures behaviour
Older DISC tests use a fixed questionnaire and four scales. Everything DiSC® uses computerised adaptive testing and eight scales arranged on a circle, which is why it can describe 12 blended styles instead of a single letter.
- 1QuestionsPeople rate statements about how they behave at work.
- 2Consistency checkIf answers on a scale don’t agree, the assessment notices.
- 3Extra questionsIt asks more on exactly those scales, so the result is precise.
- 4Eight scalesScores on eight scales place the person on the DiSC circle.
- 5Personal reportA dot, a style and priorities, written into about 20 pages.
Where DiSC comes from, and what it measures
The model goes back to psychologist William Moulton Marston, who described four patterns of emotion and behaviour in his 1928 book Emotions of Normal People. The first DiSC assessment was published in the 1970s by the company that is now part of Wiley, and Wiley has researched the model ever since. Everything DiSC® measures eight scales and places each person in one of 12 styles on the circle, because most people are a blend of two neighbouring styles.
- DDominance: D, Di, DCDirect, firm and focused on results
- iInfluence: i, iD, iSOutgoing, lively and people-focused
- SSteadiness: S, Si, SCCalm, patient and accommodating
- CConscientiousness: C, CS, CDAnalytical, careful and focused on quality
Everything DiSC® also measures priorities separately from the style, such as results, enthusiasm or accuracy. That is why two people with the same style can still get different reports: a C-style person can have a strong priority for enthusiasm, for example. DiSC describes behaviour; it does not prescribe it.
Reliability you can check
Reliability tells you whether an assessment measures consistently. Researchers usually treat .70 as the minimum. Every Everything DiSC® scale is well above it, both within one sitting and when people retake the assessment two weeks later.
- Internal consistency: median .87, all eight scales between .79 and .90
- Test-retest: .85 to .88 after two weeks
- Source: Wiley, research report for the adaptive testing assessment, 2020
Ranges drawn to scale. Higher is more reliable.
Validity: does DiSC measure what it claims?
Reliability shows that results are consistent. Validity shows that they mean what they say. Wiley has tested this in several ways, and the results are published.
Circle
The structure holds
Neighbouring scales correlate positively and opposite scales negatively, as the model predicts. Multidimensional scaling and factor analysis confirm the circular structure.
NEO PI-R · 16PF
Checked against established tests
Two independent agencies compared Everything DiSC® with two of the most respected personality inventories in psychology to establish construct validity.
71% / 88%
Observers see the same thing
In a study of leadership behaviour rated by observers, the expected DiSC style scored highest on 71% of practices and was in the top two on 88%.
~90%
People recognise themselves
Participants rate the fit of their style description as good or excellent about 90% of the time. Wiley itself notes that agreement alone is not proof, which is why the studies above matter.
Why the adaptive version is more precise
Everything DiSC® uses computerised adaptive testing: when answers on a scale are inconsistent, it asks follow-up questions on exactly that scale. In Wiley’s construct validity analysis, the adaptive assessment measured more accurately than the earlier versions.
- 32% more accurate than DiSC® Classic
- Three or more priorities can appear in a report, so results reflect people who do not fit the average for their style
Before anything is released
~14,000participants in three rounds of beta testing for a recent profile
250facilitators involved
235in-depth interviews
3,800+survey responses read
Profiles, facilitation kits and translations all go through beta testing with partners and end users before launch.
“Essentially an altogether different type of assessment.”
EFPA test review of Everything DiSC® Workplace, 2020, comparing it with traditional four-scale DISC tests
Independently reviewed and certified
Everything DiSC® Workplace was reviewed against the Test Review Model of the European Federation of Psychologists’ Associations (EFPA) and certified by DNV, an accredited certification body, in 2020. The certification was renewed on 2 January 2024 for five years.
- What it covers: Everything DiSC® Workplace, as an occupational test for development
- Who certifies: DNV. EFPA writes the standard; it does not approve tests itself
- Read it yourself: the review report is public
What DiSC is designed for, and what it is not
Use Everything DiSC® for
- Self-awareness and personal development
- Team development and communication
- Management and leadership development
- Sales and customer conversations
- Onboarding and coaching
Don’t use it for
- Hiring and selection decisions
- Predicting job performance
- Measuring intelligence, values or ability
- Labelling people or deciding who fits a team
For hiring, use an assessment built for selection, such as ProfileXT®. The EFPA review says the same: Everything DiSC® Workplace is for development.
About the research behind DiSC
Is DiSC scientifically valid?
Everything DiSC® publishes its research. Its scales show a median internal consistency of .87 and test-retest reliability of .85 to .88, above the .70 research threshold, and Everything DiSC® Workplace is certified by DNV to the EFPA test-quality standard.
Is Everything DiSC® approved by EFPA?
EFPA writes the test-review standard; it does not approve tests. Everything DiSC® Workplace was reviewed against the EFPA Test Review Model and certified by DNV, an accredited certification body.
How is Everything DiSC® different from other DISC tests?
Most DISC tests use a fixed questionnaire with four scales. Everything DiSC® uses adaptive testing and eight scales on a circle, which gives a more precise position, 12 blended styles and personal priorities.
Can we use DiSC to select candidates?
No. DiSC is designed for development and is not validated for selection. For hiring decisions, use an assessment built for it, such as ProfileXT®.
Who invented DiSC?
The model is based on the work of psychologist William Moulton Marston, who described it in his 1928 book Emotions of Normal People. The first DiSC assessment was published in the 1970s, and Wiley, its publisher today, has researched and developed it for decades.
How accurate is the Everything DiSC® assessment?
Its scales have a median internal consistency of .87 and test-retest reliability of .85 to .88. The adaptive version measured 32% more accurately than DiSC® Classic in Wiley’s construct validity analysis.
Does a DiSC style change over time?
Basic style is fairly stable, which the test-retest results show. It can shift with experience and role over longer periods, so there is usually no need to retake the assessment within two years.
Questions about the research?
If your HR team, works council or a psychologist wants to review the evidence before you decide, tell us what they need. We’ll send the reports and answer the questions.