What is psychometrics
Psychometrics is the discipline that studies how to measure psychological characteristics —aptitudes, personality, competencies— in a standardized, comparable way.
Psychometrics is the discipline that studies how to measure psychological characteristics —aptitudes, personality, competencies— in a standardized way that is comparable across people. Its object isn’t behavior itself, but the problem of measuring it well: how to assign numbers to something that can’t be seen directly (such as reasoning or customer orientation) so that those numbers mean the same thing for everyone.
The core idea: measuring what you can’t touch
Unlike measuring a height or a weight, psychological characteristics are constructs: abstract concepts that can only be inferred through indicators. We don’t measure “reasoning” directly; we measure how a person responds to a set of problems and, from there, estimate their level. Psychometrics is the set of methods that makes that estimate orderly, repeatable and comparable instead of arbitrary.
The two pillars that hold it up
The whole discipline rests on two properties that a good test must demonstrate:
| Property | Question it answers |
|---|---|
| Validity | Does the test really measure what it claims to measure? |
| Reliability | Does it measure consistently, without depending on chance or the day? |
A test can be very consistent and still measure the wrong thing, or measure the right thing erratically. That’s why both properties are evaluated separately. We develop them in what test validity is and what reliability is.
What it’s for in selection
In a selection process, psychometrics is what turns “I liked this candidate better” into “this one shows better signal in what the role needs.” It doesn’t make the decision for you: it adds a layer of comparable evidence that the CV and the interview, on their own, don’t provide. The decision still belongs to the team; psychometrics only gives that decision a common basis.
See how psychometrics translates into concrete tests.
Explore the libraryIn summary
Psychometrics is the branch that studies how to measure psychological characteristics in a standardized, comparable way. It works with abstract constructs, so it always operates with a known margin of error, not with certainties. It rests on two pillars —validity and reliability— and, applied well, it lets selection decisions rest on comparable evidence rather than impression alone. In Kokoro it’s the foundation of how the library tests are built; you can see the approach in the science behind it.