Psychometric Assessment


What is a psychometric test or assessment? The definition of 'psychometric' combines the words 'psyche', meaning 'mind', as well as the word 'meter', meaning 'measure'. Therefore, a psychometric test or assessment is a tool that measures a person's mind.

OverviewThe Science

What is a psychometric test or assessment?

A psychometric test or assessment measure psychological characteristics such as personality traits, behavioral styles, cognitive abilities, motivations etc. The word psychometric literally means psychological measurement. Thomas assessments measure a wide range of different characteristics, learn more about our solutions here

The definition of 'psychometric' combines the words 'psyche', meaning 'mind', as well as the word 'meter', meaning 'measure'. Therefore, a psychometric test or assessment is a tool that measures a person's psychological characteristics. For example, psychometric tests and assessments can measure characteristics such as personality traits, cognitive abilities, behavioral styles and more.

There is a distinction between a psychometric test and a psychometric assessment. The main difference is that a test measures your maximum performance using tasks that have right or wrong answers. An assessment will typically use a questionnaire-format, asking you to rate your agreement levels with certain statements, or perhaps indicate how frequently you feel a certain way.

Examples of psychometric tests include cognitive ability tests, aptitude tests, logic tests and reasoning tests. Examples of psychometric assessments include personality assessments, emotional intelligence assessments and behavioral preference assessments. Psychometric tests and assessments aim to put your scores or responses into context, for example comparing you to other people. A test or assessment that compares you to others is known as a norm-referenced (normative) test; how did your performance or responses compare to a comparative group of people, like the working population of your country. A self-referencing (Ipsative) test or assessment will compare your performance or responses to your individual performance or response patterns. A test or assessment that focuses on a very specific set of skills or knowledge is called domain-referencing. An example would be a driving test as you have to achieve a pre-established level of performance and knowledge to meet set criteria.

Best practice when using psychometrics

There are best practice guidelines for using psychometric tests and assessments in an occupational context. Guidelines for the best practice use of psychometric assessments are developed and published by regulatory bodies such as the British Psychological Society (BPS), the European Federation of Psychologists Associations (EFPA), the Health Professionals Council of South Africa (HPCSA) and so on. 

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Test author: Thomas M. Hendrickson

Year of construction: 1958


Background and theory:

In the late 1950s and early 1960s, Dr. Thomas Hendrickson developed William Moulton Marston’s DISC theory to produce the Thomas Personal Profile Analysis (PPA) for the work place.

Marston's original theory stated that actions based upon emotions are an individual's biosocial response to supportive or hostile social environments. These actions determine how the individual interacts with the environment. It was theorised that the way in which the individual interacts with the environment takes four basic directions: tendencies to dominate, influence, submit and comply. Marston published his book 'Emotions of Normal People' in 1928, which described his theory of human consciousness in comprehensive detail.

The PPA 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 behavioral preferences in terms of four domains: Dominance, Influence, Steadiness and Compliance. 


The Thomas PPA is a forced-choice instrument which uses an ipsative referencing method – an individual's response patterns are compared to themselves rather than the scores of a comparison group. Individuals are asked to select one adjective which they believe describes them most and one which describes them least.

In order to complete the PPA, individuals choose two trait adjectives from a block of four, one 'most like' and one ‘least like’ them. This process is repeated 24 times, giving 48 choices from a total of 96 words.

The PPA is available electronically via the web and in paper-and-pencil format. Thomas International has also developed the PPA+ format which is suitable for people with a reading age of 11+ and for candidates who are fluent in English but for whom English is not their first language.

Reliability and validity:

The Thomas PPA has been subject to rigorous scientific testing to determine its reliability and validity as a psychological assessment. The PPA is registered with the British Psychological Society (BPS) after it was audited against the technical criteria established by the European Standing Committee on Tests and Testing, part of the European Federation of Psychologists' Associations.

Thomas International conducts on-going psychometric research with the PPA in partnership with the Psychometrics Centre at Cambridge University.

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