The ultimate guide to assessments
An assessment is a standardised measurement of a candidate's characteristics, such as cognitive ability, personality, motivation and culture preference. Organisations use assessments in hiring to decide more objectively who is suitable for a role. Validated assessments predict job performance demonstrably better than a CV or an unstructured interview.
This guide is written for recruiters, HR managers and hiring managers who are considering assessments or want to improve how they use them. You will read what an assessment is, which types exist, which tests hold up scientifically and how to choose the right one. Updated September 2026.
What is an assessment?
An assessment maps a candidate's characteristics with questionnaires and tests that are identical for everyone. The outcome is an objective picture of strengths and weaker points, set against what the role requires. You no longer rely on what someone says they can do, but on what the measurement shows.
Say you are hiring an accountant. Accuracy is decisive for that role. In an interview almost every candidate will claim to be precise. A personality test that measures conscientiousness gives an independent answer to that question. That is exactly what an assessment is for.
Assessments have been in use since the First World War, when armies screened recruits with personality questionnaires. Business adoption followed decades later. The range of instruments has grown so much since then that the main question is no longer whether to use an assessment, but which assessment fits your role and your process.
What types of assessments exist?
Broadly there are three types, grouped by the purpose they serve. This guide is mostly about the selection assessment, but the other two are common in practice and regularly get mixed up.
| Type | Purpose | When | Typical components |
|---|---|---|---|
| Selection assessment | Determine whether a candidate fits the role and organisation | During the hiring process | Personality test, cognitive ability test, culture and values questionnaire, situational judgement test |
| Development assessment | Map an employee's growth potential | During employment | Competency test, personality test, in-depth interview, role play |
| Career assessment | Advise on a next career step | At a job change or reorientation | Similar to selection, focused on talents and interests |
A common mistake is using a development assessment to select candidates. Development instruments are built to start conversations, not to predict who will perform best. The reverse also holds, a selection test says little about how someone can grow.
What does an assessment consist of?
A selection assessment usually combines several instruments. Each component measures something different and has a different predictive value depending on the role.
Personality test
Measures how someone behaves, communicates and responds to pressure. Candidates indicate to what extent statements apply to them. There are no right or wrong answers. Good tests include checks for socially desirable answering and approach the same trait from several angles.
Cognitive ability test
Also called an intelligence test or aptitude test. Measures under time pressure how well someone reasons with numbers, words and figures. Cognitive ability is one of the strongest predictors of job performance across almost all roles. Read how to use it fairly in our article on intelligence tests in recruitment.
Motivation and core values
Measures what motivates someone and what they find important in work. A widely used framework is Schwartz's theory of basic values, which distinguishes ten universal values such as self-direction, achievement, security and benevolence. A large gap between a new hire's values and those of the organisation is a common reason for early departure.
Culture fit
Measures whether a candidate's working style and preferences match how your organisation actually works. Think of hierarchy, pace, degree of structure and way of collaborating. Someone who struggles under tight direction fits better in a flat organisation, however strong the rest of the profile is.
Situational judgement test
Presents realistic work scenarios and asks how the candidate would act. This measures judgement and behaviour in context, feels relevant to candidates and is hard to game.
Game-based assessment
Measures cognitive and personality traits through short interactive tasks instead of questionnaires. Candidates find it more pleasant and completion rates are typically higher. Selection Lab offers game-based assessments per construct, such as the Problem Solving Game, the Adaptability Game and the Culture Fit Game.
Which personality test is suitable for selection?
Not every well-known personality test is suitable for selecting candidates. Two criteria decide whether a test is usable. Validity, does the test measure what it claims to measure and does it predict job performance? And reliability, does the same person get roughly the same result when retested?
| Test | What it measures | Scientific basis | Suitable for selection | Suitable for development |
|---|---|---|---|---|
| Big Five | Five personality dimensions (OCEAN) on a scale | Strong, decades of independent research | Yes | Limited, personality is stable |
| HEXACO | Six dimensions, Big Five plus honesty-humility | Strong, growing body of studies | Yes | Limited |
| MBTI | Sixteen personality types | Weak, low test-retest reliability | No | Self-insight only |
| DISC | Observable behaviour in four styles | Limited, little independent validation | No | Yes, for teams and communication |
| Insights Discovery | Preferences and pitfalls in four colours | Limited, mostly the provider's own research | No, built for self-insight | Yes |
| Management Drives | Six drives in colours | Little independent research | No | Yes, for team and organisation development |
The Big Five and HEXACO are the only two in this comparison that qualify for selection. Both measure personality as dimensions you score on, not as types you are sorted into. That makes candidates comparable and produces scores that predict job performance. For selection, conscientiousness and, in HEXACO, honesty-humility are the dimensions to watch most closely.
Colour-based tests such as DISC and Insights are popular because they are instantly recognisable. For team days and communication training that is a strength. For predicting who will do a job well the evidence is missing, and that is what a selection process needs.
Source: Schmidt & Hunter, 1998; Sackett et al., 2022; Ashton & Lee, 2007
How does a cognitive ability test work in an assessment?
A cognitive ability test consists of several short sections completed under time pressure. Work experience plays no role, the test measures how quickly and accurately someone processes new information. These are the most common sections.
- Number series, spot the pattern in a row of numbers and fill in the next one
- Figure series and matrices, choose the correct figure based on a movement or similarity pattern
- Analogies, recognise the relationship between two words and apply it to a second pair
- Syllogisms, draw the only logically valid conclusion from two statements
- Antonyms, choose the word with the opposite meaning
- Diagrams, show the relationship between concepts in overlapping circles
- Word problems, solve a calculation wrapped in a piece of text
An example of a number series is 3, 6, 12, 24 followed by a question mark. The hidden rule is multiply by two, so the answer is 48. One item like this measures logical reasoning and numeracy at the same time.
An IQ test and a cognitive ability test look alike, but the output differs. An IQ test expresses intelligence in a single number. A cognitive ability test sets the score against a norm group or a job profile, so you can see whether the level is sufficient for the role. For selection that is the useful question. Someone far above the level of the role gets bored sooner and leaves earlier.
Candidates can practise for a cognitive ability test and it raises their score slightly, mostly the first time. That is no reason to discourage practice. Someone who knows the question format loses no points to unfamiliarity and shows what they can really do. It is fairer to offer every candidate a practice version than to leave it to chance who has practised.
Source: Hausknecht et al., 2007
What are the pros and cons of assessments?
An assessment is an investment in time and money, so asking whether it pays off is fair. The benefits are well researched. The drawbacks are practical and can largely be managed with the right choice.
| Pros | Cons |
|---|---|
| Predicts job performance better than a CV or unstructured interview | Costs money per candidate, prices vary widely by provider and type |
| Reduces the chance of a mis-hire and the cost of early departure | Adds a step to the process, which can pinch on a tight timeline |
| Produces targeted interview questions based on strengths and weak points | Choosing the right type takes time, the wrong choice measures the wrong thing |
| Gives every candidate the same questions and so reduces the influence of bias | Some groups score lower on average on cognitive tests, monitoring is needed |
| Candidates feel taken seriously and can use the report themselves | A long or unclear test increases drop-off, especially for scarce profiles |
The argument that carries the most weight is the mis-hire. A wrong hire costs salary, onboarding time, coaching and recruiting again. What that bill amounts to in your organisation depends on role and level, but in almost every case it is a multiple of what an assessment costs.
What is the difference between an online and an in-person assessment?
An online assessment is completed by the candidate alone, at a time and place of their choosing, usually within 45 minutes. An in-person assessment takes place in an assessment centre with interviews, role plays and tests, guided by a psychologist, and often takes a full day.
Online is cheaper, scalable and easy to build into an existing process. Several candidates complete it at once and the result lands directly in your ATS. What you miss is observation of non-verbal behaviour and the chance for candidates to ask questions along the way.
In-person is more thorough and gives a richer picture, but requires specialised staff and sometimes actors. For executive roles or a single high-stakes appointment that can be worth it. For the majority of vacancies, and certainly at volume, an online assessment is the logical choice. An online measurement early in the process followed by a structured interview combines the strengths of both.
When should you use an assessment in the hiring process?
As early as is reasonable. Many organisations only bring in the assessment after two or three interviews. By then the recruiter has already formed an opinion and the result serves to confirm rather than inform. Most of the value of objective information is lost at that point.
Deploy the assessment right after an initial screening, before the first substantive interview. That way you already know where the strengths are and where to probe critically. If the report says a candidate for a control function works with little structure, that is the topic of the conversation. In high-volume hiring, a short screening via SmartChat by Selection Lab, the conversational AI via WhatsApp, followed by a short assessment works as a first filter without recruiter involvement.
What should you look for when choosing an assessment?
The market is large and so are the differences in quality. Five questions help separate the good from the rest. For a fuller overview of providers, see our top 20 assessment providers in the Netherlands and our checklist of 10 things to watch out for when buying assessments.
- Does the test predict job performance? Ask for the validation research. A provider that cannot or will not share it is out.
- Is the test reliable? The same candidate should get a comparable result when retested. In the Netherlands a positive COTAN review by the NIP is a good sign.
- Does the test fit the role? A warehouse picker and a financial controller need different instruments. One test for all roles lowers predictive value.
- What is the candidate experience like? Look at duration, mobile usability and whether candidates get their results back. Drop-off during the assessment signals that the test is too long or too unclear.
- Is it legally sound? Under GDPR you need a legal basis and must inform candidates about what you measure, why and how long you keep the data. AI systems used in recruitment and selection are classified as high-risk under the EU AI Act, which sets requirements for explainability and human oversight.
Unsure whether you need a broad assessment or whether one targeted test will do? Read the difference between a skill test and an assessment.
How does Selection Lab use assessments?
Selection Lab is an Amsterdam-based HR-tech platform that combines validated assessments, game-based assessments and conversational AI screening via WhatsApp in one selection flow, connected to your ATS. Every test we offer meets the criteria in this guide. Per role you set the balance between predictive power, candidate experience and fairness.
More than 500 organisations work with Selection Lab. Dentons saw quality of hire rise by 13.5%. DPD reached an 89% completion rate by combining assessments with SmartChat. FrieslandCampina screened 23,000 applicants across 18 countries through one process.
Want to see how an assessment fits into your hiring process? Book a demo and we will walk through your current process and the options in half an hour.
Frequently asked questions about assessments
What is an assessment?
An assessment is a standardised measurement of a candidate's characteristics, such as cognitive ability, personality, motivation and culture preference. Organisations use assessments in hiring to decide more objectively who is suitable for a role.
What types of assessments exist?
There are three main types. A selection assessment determines whether a candidate fits a role. A development assessment maps an employee's growth potential. A career assessment advises on a next career step. You can also distinguish online assessments from in-person assessments in an assessment centre.
How long does an online assessment take?
A short screening assessment takes five to fifteen minutes. A standard combination of a personality test and a cognitive ability test takes twenty to forty minutes. A full assessment with several instruments can take 45 to 90 minutes. An in-person assessment in an assessment centre often takes a full day.
Which personality test is most reliable for selection?
The Big Five and HEXACO have the strongest scientific basis and predict job performance. Type tests such as MBTI and colour tests such as DISC and Insights Discovery are not suitable for selection, because evidence for their predictive value is missing or their test-retest reliability is low.
Can you use an assessment to reject candidates?
Yes, provided you comply with GDPR and the test does not discriminate. You need a legal basis, usually legitimate interest, and you must inform candidates in advance about what you measure and how long you keep the data. Never use the result as the only filter and combine it with a structured interview.
Can candidates practise for an assessment?
For a cognitive ability test, yes. Practice raises the score slightly, mostly the first time, because the candidate gets used to the question format and pace. It is fairer to offer every candidate a practice version. For a personality test practice has little effect, there are no right or wrong answers.
How much does an assessment cost?
Prices vary widely by provider, type and volume. A short online assessment costs a fraction of a day in an assessment centre with a psychologist and actors. Weigh the price against what a mis-hire costs in salary, onboarding and recruiting again. That bill is almost always a multiple of the price of an assessment.
Written by Lotte Welten, CEO and co-founder at Selection Lab.
