A candidate makes a strong impression during an interview, comes across as confident, and expresses clear opinions. Are they the right person for the job? Intuition says yes. Data may tell a different story. Why is neither human judgment nor artificial intelligence enough when selecting employees? We explain how to recognize a quality psychodiagnostic method and what HR professionals and managers consider important when choosing one.
What Is Psychodiagnostics and Why Do We Need It?
Psychodiagnostics is an applied branch of psychology concerned with observation, measurement, and assessment. Its purpose is to identify and measure psychological characteristics and states—in other words, aspects that remain hidden during an ordinary conversation.
Why isn’t the intuition of an experienced HR professional enough? Because even the most experienced recruiters are subject to various cognitive biases:
- Halo effect—one prominent characteristic (confidence, charm, or eloquence) overshadows everything else and influences the overall impression.
- Implicit personality theory—we automatically infer other traits from a single characteristic (“They’re assertive, so they must also be a good leader”).
And what about artificial intelligence? AI can do a great deal these days, but it is not a qualified psychologist. Developing a reliable diagnostic method takes months or even years—collecting data, conducting validation studies, establishing norms, and making revisions. None of this can be generated with a single prompt.
How to Recognize a Quality Assessment Method
Not every questionnaire reliably measures what it claims to measure. When selecting a psychodiagnostic method, there are three things you should look for:
- Reliability—indicates whether a method measures consistently and accurately. Imagine a kitchen scale. If you place the same apple on it today and tomorrow, it should show the same value. If it reads 200 grams one day and 350 grams the next, you cannot trust the result. The same principle applies to questionnaires: if someone completes the same questionnaire several weeks apart, their results should not differ significantly. Reliability can be assessed statistically in several ways. The developer of a method should therefore always provide numerical evidence of its reliability.
- Validity—indicates whether a method actually measures what it claims to measure. Let’s stay with the scale analogy. Even if the display consistently shows 200 each time you place the apple on it, we should still ask: is the “scale” really measuring weight? What if it isn’t a scale at all, but a device measuring the apple’s circumference in centimeters? Similarly, a questionnaire may produce consistent results (because it has high reliability) while measuring something other than what it claims (because it has low validity). For example, instead of conscientiousness, a questionnaire might actually capture perfectionism. With recruitment assessment tools, it is also particularly important to establish whether the results are related to actual job performance.
- Technical manual—explains the foundations of the method. A quality manual describes the theory underlying the assessment, provides information about its psychometric properties (such as reliability and validity), and explains which reference group your results are compared with (norms). This helps you understand how to interpret the results correctly. A reputable provider of psychodiagnostic assessments will readily share the manual. If they claim it is a “trade secret,” consider it a warning sign.
And if you’re unsure, ask the experts. Professional groups of psychologists are a good place to start, as questions about specific assessment methods are common. Don’t be surprised if your question sparks a lively discussion—that’s part of professional debate. Just make sure to verify the arguments using multiple sources.
What Do Those Who Use Psychodiagnostics Say?
Our small-scale survey of 61 HR professionals and managers in the Czech Republic who use psychodiagnostic assessments revealed that:
- 77% select methods based on recommendations from colleagues and other professionals in the field.
- 84% consider psychometric properties the most important factor.
- 2% would entrust the entire development of a psychodiagnostic method to artificial intelligence.
The responses clearly indicate that practitioners prefer validated methods over quick solutions.
Psychodiagnostics does not replace interviews or the experience of HR professionals. It complements them by revealing what cannot be seen with the naked eye and helping to reduce biases that none of us can completely avoid. However, it only works when the method is reliable and valid. That’s why, when choosing a method, it pays to ask questions—quite literally.