Online psychometric tests look deceivingly simple from a user’s perspective. Just answer some questions, click a button and voila, there’s a full and elaborate report, tailored to your uniqueness and often comparing you with thousands of others. This is exactly how we want it to be for you!

The underlying reality is that true psychometric tests are highly knowledge-intensive technological products, resulting from input from the full stack of psychology, psychometrics, webserver management, custom software development, textual interpretations, graphical representations, UX design and large scale data management. For almost 20 years we are doing just that.

Our entire team of experts, employees, freelancers, authors and associated companies guarantee that our tests are as easy and simple to use as you experience them to be, and reach well over 100.000 users globally. Reliably and valid. Every day.

Management and company owners

Dr Edwin van Thiel

Edwin van Thiel - 123test

As a founder of the 123test company, Edwin has seen the company grow from a mere 100 to more than 100.000 visitors a day. With a PhD in artificial intelligence (cognitive psychological research) and additional specializations in psychometrics and tests for the web he's an all-round specialist and author.

Leading 123test as CEO he enjoys strategy, as well as the push and pull of daily business management. He’s also a proud sponsor of the International High IQ Society as its president.

Bart Dekker

Bart Dekker - 123test

Bart holds a M.Sc. degree in Occupational Psychology and has been working on psychometric tests ever since he graduated. On the job he greatly expanded his knowledge of the full stack of online test development, never hesitating to take on any aspect of the matter.

As CPO he's responsible for anything product, which means that besides principal test development he mines a lot of data and guards product integrity.

Theo den Hollander

Theo den Hollander - 123test

Having worked with different companies first, Theo (M.Sc. Software engineering) designed and lead the development of several smaller and large-scale software architectures. At 123test he widened his expertise with respect to developing and hosting web-applications able to withstand high volume traffic, guaranteeing unrivaled uptime and website speed.

As CTO Theo is responsible for the entire technical backbone of 123test, i.e., the software product line, to ensure consistency, quality and productivity in it.

Other contributors and acknowledgements

Over the years we have welcomed the contributions of many experts in the fields of psychometrics, scientific research and test development. They brought about highly specific knowledge on selected topics, others we provided the opportunity to gather research data through our websites or to use our tests for scientific research and publications. There are too many to list all, but we acknowledge the contributions of the people below who were shortly, or for several times, a member of 'the team'.

Dr Pieternel Dijkstra

Dr. Pieternel Dijkstra received her PhD in the Social Sciences from the University of Groningen in 2001. Since then she has studied several social psychological issues in various contexts. She strongly believes that scientific knowledge and its applications should benefit all. Pieternel aided in constructing tests, writing articles and providing advice on several diverse topics over the years.

Dr Arnold Brouwer

Dr. Arnold J. Brouwer is an assessment expert in educational testing and psychological testing. He is an all-round researcher, developer and consultant of methods and techniques for analyzing, optimizing and auditing reliable and valid assessments.

Arnold used an elaborate personality test, work values test, competencies test and team roles test of 123test in his research that lead to his doctoral thesis, a book chapter and one more additional scientific paper. These are listed below:

Systems-oriented talent management: a design and validation study  (PDF

The Design and Validation of the Renewed SystemsOriented Talent Management Model

How Age Affects the Relation between Personality Facets and Work Values of Business and Private Bankers

Tom Luken

Tom Luken has dedicated a large part of his life to career development. How do choices thread together in careers and lives? What role do unconscious motives and processes play in this? What determines that some people become successful and/or happy while others fail? How do people learn to look ahead and direct their own lives and careers? These are some of the themes he has been working on since 1975. Over the past decades, he has regularly reported on his research and its results. This has resulted in about 175 publications.

Professor Dr Roos Vonk

Roos Vonk is a professor of social psychology at Radboud University Nijmegen. She conducts scientific research and teaches students, on topics including: the first impression, self-knowledge, behavioral changes and human-animal relationships. She makes scientific knowledge accessible and applicable for a broad audience. Roos collected data and published diverse tests for limited periods at the Dutch language version of 123test.

M.A. Marit op de Beek

Marit contributed as a freelancer (Maxit Psychology) to several tests on topics ranging from IQ to career choice. She worked for several other test publishers such as Cubiks and Hogrefe too before shifting her career towards consultancy, coaching and talent management.

Dr René Butter

René Butter received his doctorate from K.U. Leuven in the field of quantitative methods in psychology. He has also accumulated a lot of knowledge and experience in the field of practice-based research. He has been working as a trainer, coach and (career) advisor for over 20 years, both for groups and individuals. He is also active as an assessment psychologist and teacher. René helped to creating original and very reliable tests and tools, all with high utility and practicality.

Dr Dick Barelds

Dick Barelds received his PhD in 2003, and has been working as an assistant professor ever since at the University of Groningen, first at the Differential Psychology group, and since 2010 at the Industrial and Occupational Psychology group. His research interests include personality, intimate relationships, and physical attractiveness, often in combination with each other. Dick has contributed directly and indirectly to several tests. often in conjunction with Pieternel Dijkstra.

Rob Williams

Rob Williams Assessment Ltd, led by published psychometric author Rob Williams, are specialists in designing bespoke situational judgement tests, personality test and aptitude test design. Well-designed SJTs are widely considered to be fairer than other assessment formats and to have higher engagement with their target audiences. Rob authored this article on Situational Judgement tests and a career focused test. Rob is an Associate Fellow of the British Psychological Society and a Chartered Psychologist.

Dr Wouter Schoonman

Wouter Schoonman is highly authoritative and knowledgeable on assessments, psychometrics and professional conduct in the assessment industry. His advice and practical input has contributed to the quality of several IQ assessment tests. He got his PhD through research on computerized adaptive testing (CAT).

Dr Roy van den Brink Budgen

Dr Roy van den Brink-Budgen ( is highly authoritative in the field of critical thinking. His experience is regarded unrivalled in many ways. He authors innovative resources, including many articles and books on the subject and also effectively links creative and critical thinking. He is both an author of critical thinking assessment materials as well a teacher, and is active across the globe. Roy is the author of this article on Critical thinking.

Dr Deborah DeLong

Debbie DeLong is professor of marketing at Chatham University and used the team roles test in her research which led to the following publication:

Transitioning to Remote Teams in Principles of Marketing; An Exploratory Psychometric Assessment of Team Role Effects on Face-to-Face and Online Team Performance