Updates to the Thomas Behaviour Assessment | Thomas.co

We’re very proud of the fact that we’ve built our business on robust, proven psychological science, but we’re not ones to rest on our laurels. We are always looking at ways to improve and ensure our science is kept up to date and valid. To this end, we’re updating the English versions of our Behaviour assessment, also known as the PPA, or Personal Profile Analysis. 

What is the PPA?

The PPA, or the Thomas Behaviour assessment, determines whether individuals see themselves as responding to workplace situations that they perceive to be favourable or challenging, and reveals whether their response patterns are active or passive; thus classifying the individual’s behavioural preferences in terms of four domains: Dominance, Influence, Steadiness and Compliance. The assessment offers a series of blocks of four adjectives and asks individuals to select one which they believe describes them most, and one which describes them least.

Why have we made these updates?

The English versions of the assessment have been updated due to language changes which naturally occur over many years. Regular reviews, and if necessary, updates to different language versions of all assessments are required to ensure they remain psychometrically robust. This is something that any good test provider should be doing to maintain and update their assessments as part of their commitment to quality for their customers. Note that this update doesn’t mean that the Thomas Behaviour assessment wasn’t robust or had decreased in scientific validity.

What’s involved in the update?

If you’re familiar with the assessment, you may notice that many of the words offered for individuals to choose from have changed. Those who have completed the PPA more than once are most likely to notice this change, but for the majority of assessment takers, these changes will be completely transparent. You should notice that the new adjectives are more current and in line with language used today. None of the reports or content that our customers use has been changed in any way by this update. 

How reliable is the updated assessment?

Internal Consistency: Internal consistency measures how well different items relate to the same construct it’s intended to measure.  

A study in September and October 2020 was used to assess the internal consistency of the new form. 202 participants completed the assessment, and the alpha coefficients were calculated as shown here  

Dominance α = .90  

Influence α = .86  

Steadiness α = .84  

Compliance α = .83.  

The median scale alpha was 0.85. This provides strong support for the reliability of the assessment.  

Is the assessment registered with the British Psychological Society? 

This updated version is registered with the BPS and audited against technical criteria established by the European Federation of Psychologists’ Associations. As part of the registration process, we presented evidence to the BPS that the updated assessment is equivalent to the previous version. i.e., anyone who complete the old version and the new version should have near identical results. 

What does this all mean for users of the assessment? 

Realistically, few, if any users will notice any changes. By using the updated version, assessment takers will be completing a more accurate and reliable assessment which we can be even more scientifically confident in. As previously noted, our customers will not see any changes to the content and reports that are produced from the assessment results. 

Are there any updates or changes to other Thomas assessments? 

The psychology team at Thomas continuously review our assessments to ensure they are scientifically robust and valid. Along with the recent recertification of the psychometric behavioural assessment with the BPS, our HPTI or Personality assessment is also under review with the BPS. We are also working on numerous new or updated translations of the PPA, HPTI and GIA to ensure the continued robustness of our assessment offering globally.