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Best practice in psychometrics

Articles on assessment science, fair selection and what's changing in the industry — written by our business psychologists.

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Featured AI & assessment · 3 min read

Can candidates cheat psychometric tests with AI — and what should employers do about it?

Generative AI has changed unproctored online testing. We look at what the evidence says about AI-assisted responding, which test types are most exposed, and the detection and design measures that keep results valid.

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How-to guides 5 min read

How to read a psychometric test report: percentiles, stens and score bands

A psychometric test report packs a lot into a few numbers: a percentile, a sten, a band, perhaps a speed or accuracy figure. Read well, they tell you how a candidate compares with a relevant group and where to probe at interview. Read badly, they invite false precision. Here is how to read a psychometric test report with confidence.

AI & assessment 5 min read

Algorithmic hiring tools and bias: what employers should check before they buy

Algorithmic hiring tools promise faster, more consistent screening, and some vendors promise less bias than human recruiters. The evidence shows they can deliver on consistency and can also reproduce bias at scale. The difference usually lies in what the employer checked before buying.

AI & assessment 5 min read

Can AI write psychometric test questions? Automatic item generation and its limits

Large language models can draft a plausible test question in seconds, and automatic item generation has been producing items by the thousand for over a decade. But a question that looks right is not the same as one that measures well. Here is what the research shows about AI-written test questions, and where the human work still lies.

Industry news 5 min read

AI in recruitment: what the EU AI Act and UK rules mean for employers

Using AI in recruitment now carries specific legal duties on both sides of the Channel, and the timetable has just moved. Here is where the EU AI Act and the UK rules stand as of October 2026, and what employers should be doing now.

Assessment science 5 min read

Personality type or personality traits? What the evidence says about the two approaches

Personality type and personality traits are two different ways of describing the same people. Type-based questionnaires sort people into categories; trait measures place them along continuous scales. The evidence suggests each has a natural home, and the choice matters most when a decision about someone's job depends on it.

How-to guides 5 min read

Concentration and vigilance tests for safety-critical roles

In safety-critical work, the most dangerous moments often come after long stretches when nothing happens. Concentration and vigilance tests measure the ability to stay alert through those stretches. Here is the science behind them, how they are used in train driver selection, and how to make decisions from them responsibly.

How-to guides 5 min read

Error checking tests: how to measure attention to detail

Almost every job advert asks for attention to detail, and almost every candidate claims it. Error checking tests replace the claim with evidence. Here is what they measure, where they predict performance, and how to use them without overstating what a short test can tell you.

How-to guides 5 min read

Mechanical comprehension and fault finding tests for technical roles

Mechanical comprehension and fault finding tests are the workhorses of technical selection, from engineering apprentices to maintenance technicians and rail staff. They measure different things, and the research shows where each adds value and where it needs support from other evidence.

How-to guides 5 min read

Spatial reasoning tests: what they measure and which roles need them

Spatial reasoning tests are less familiar to most employers than verbal or numerical tests, yet decades of research link spatial ability to success in engineering, design and technical work. Here is what spatial reasoning tests measure, what the evidence shows and which roles genuinely need them.

How-to guides 5 min read

Inductive, deductive and abstract reasoning tests: what's the difference?

Inductive, deductive and abstract reasoning tests are often used interchangeably, but they measure different things. Knowing the difference helps employers choose the right test for the role and interpret the results sensibly. Here is how they differ and what the research behind them says.

How-to guides 5 min read

Verbal reasoning tests: what they measure and when to use them

Verbal reasoning tests are a staple of graduate, professional and managerial selection. They are quick to administer and well supported by research, but they are only useful when the role genuinely depends on reading and reasoning with written information. Here is what they measure and when to use them.

How-to guides 5 min read

Numerical reasoning tests: what they measure and how employers should use them

Numerical reasoning tests are among the most widely used assessments in graduate, financial and analytical hiring. Used well, they add real predictive value; used carelessly, they screen out capable people for the wrong reasons. Here is what they measure and how to use them well.

Fair selection 5 min read

Differential item functioning: how test developers find biased questions

Differential item functioning is the main statistical tool test developers use to find questions that may be biased against a group of candidates. It works by asking a precise question: do people of the same ability, from different groups, have the same chance of getting this item right?

Fair selection 6 min read

Adverse impact in psychometric testing: what it is and how to monitor it

Adverse impact in psychometric testing occurs when a selection method produces noticeably different outcomes for different groups of candidates. It is not proof of discrimination, but it is a signal every employer using tests should be monitoring. Here is what it means legally, how to measure it, and what to do about it.

Assessment science 5 min read

Speed or power? What time limits on psychometric tests really measure

Almost every online ability test has a time limit, but the limit does very different jobs depending on how the test is designed. Understanding the difference between speed and power tests helps employers choose the right test, read the results correctly and handle requests for extra time fairly.

Assessment science 5 min read

Why a test score is a range: the standard error of measurement explained

Every psychometric score carries some measurement error, and the standard error of measurement tells you how much. Understanding it changes how you read a score: not as a single exact point, but as a range within which the candidate's true level most probably lies.

Assessment science 5 min read

Parallel forms and item banks: why a good online test has many versions

If every candidate who takes an online test sees the same questions, those questions will not stay secret for long. Parallel forms and item banks are how test developers keep unsupervised online testing secure without making it unfair, and the evidence behind them is worth understanding before you choose a test.

Assessment science 5 min read

Item response theory explained: what it means for employers who use tests

Item response theory sits behind many modern online tests, including adaptive tests that give each candidate a different set of questions. You do not need the mathematics to use it well, but knowing what item response theory does, and what it cannot do, helps you ask suppliers the right questions.

Assessment science 5 min read

Item analysis: how test developers decide which questions make the cut

Most questions written for a new psychometric test never reach a candidate. Item analysis is the set of statistical checks that decides which ones survive, and understanding it explains a great deal about why a well-built test behaves the way it does.

Assessment science 5 min read

How a psychometric test is built: from job analysis to published test

A psychometric test that takes candidates twenty minutes can take a developer a year or more to build. Knowing how a psychometric test is built, and what evidence each stage should leave behind, is the quickest way for an employer to tell a well-founded instrument from a set of questions with a logo on top.

Assessment science 3 min read

Game-based assessments in recruitment: what the research shows

Game-based assessments measure candidates through play — short interactive tasks that record not just answers but behaviour. The marketing claims run ahead of the science, but the science is now substantial enough to say what these tools genuinely add to a selection process, and where the cautions lie.

Assessment science 4 min read

Assessing for potential: building a picture no single test can give you

Hiring for potential means predicting what someone will become, not auditing what they already are. No single instrument does that. The research case is for a battery — ability, personality, judgement, skills and game-based measures — each answering a question the others cannot.

Assessment science 5 min read

Situational judgement tests in recruitment: what the research shows

Situational judgement tests present candidates with realistic work dilemmas and ask them to judge the possible responses. They sit between the abstraction of an ability test and the expense of an assessment centre — and the research explains why they have become a fixture of high-volume and high-stakes selection alike.

Assessment science 4 min read

Ability tests in recruitment: what the research shows

For decades, cognitive ability tests were held up as the single best predictor of job performance. Recent research has revised that claim in important ways — without dislodging ability testing from the core of a well-designed selection process. Here is where the evidence now stands.

Assessment science 4 min read

Personality questionnaires in recruitment: what the research shows

Personality questionnaires divide opinion like no other selection tool: dismissed as horoscopes by some, treated as X-rays by others. The research supports neither view. Used well, they add real predictive value; used badly, they measure little more than a candidate's theory of what the employer wants to hear.

How-to guides 6 min read

Why Word, Excel, Python and AI skills matter at work: what the research shows

Four skill areas keep surfacing in labour-market research: word processing, spreadsheets, programming, and — most recently — working with AI. The evidence shows each matters across a far wider range of roles than commonly assumed, though to different degrees. This piece reviews what the published research actually says.

How-to guides 5 min read

Assessing work skills: Word, Excel, Python and AI

CVs list tools; they rarely tell you whether a candidate can use them. Here is how to assess the skill areas that now appear in almost every job description — and how our work skills suite measures each one.

Assessment science 3 min read

Norm groups: why the comparison group matters as much as the score

A percentile is not a property of a person. It is a statement about a comparison — and the comparison group is doing more of the work than most report readers realise.

How-to guides 3 min read

How to run a 360 feedback programme people actually trust

Most 360 programmes fail for the same reason, and it is not the questionnaire. It is that nobody was clear what the feedback was for.

Industry news 3 min read

Game-based assessment: engagement gimmick or measurement breakthrough?

Game-based assessment has moved from novelty to procurement shortlist. The engagement benefits are real and reasonably well evidenced. The measurement claims deserve more scrutiny than they usually get.

Fair selection 3 min read

Reasonable adjustments in online testing: a practical guide for employers

The duty is anticipatory, which means it applies before anyone asks. Most employers get the legal principle right and the operational detail wrong.

How-to guides 3 min read

SJT or ability test? Choosing the right assessment for the role

They measure different things, fail in different ways, and suit different roles. The choice is usually clearer than it looks — and the answer is often both.

Assessment science 3 min read

What makes a psychometric test valid? Reliability, validity and fairness explained

Three words get used interchangeably in assessment marketing and mean quite different things. Understanding the difference is the difference between buying a test and buying a claim.

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