Selection and Aptitude Diagnostics
By Redaktion techport.ai, HR-Beratung · Last updated on
The unstructured job interview is the most popular selection method and one of the worst. It primarily measures how well someone converses and how similar they are to the interviewer. Research on this has been unequivocal for decades, yet most companies make decisions based on it for contracts worth six-figure sums.
Aptitude diagnostics means defining what the role requires before the interview, and then using methods that precisely measure that: structured interviews with rating anchors, work samples, and validated tests where necessary. This is less effort than it sounds and makes selection decisions transparent, including to the works council and in court.
How to spot it
- Two interviewers reach opposing conclusions after the same interview.
- Poor hires are identified after six months, and no one can say what was overlooked in the selection process.
- The applicant tracking system offers AI ranking, and no one knows what criteria it uses to sort.
- Rejections cannot be justified because no criteria are documented.
Why this happens
Selection is considered a matter of experience. Managers trust their judgment, and no one measures if it is accurate, because feedback only comes months later and is never linked back to the interview. AI functions are supplied and activated by providers without anyone reviewing the criteria.
Our approach
- Refine the requirements profile. From the job description and job architecture, we derive the five to seven competencies crucial for success in the role.
- Define the process. For each competency, we select a method: structured interview question with a rating scale, work sample, or test. We create guides that interviewers can use without training.
- Classify AI usage. Where software pre-sorts or evaluates, we examine the criteria, data basis, and legal classification. Under the AI Regulation, applicant selection systems are high-risk systems, with obligations applicable from December 2027. The works council's co-determination rights regarding selection guidelines already apply today.
- Measure quality. We link selection evaluations to subsequent performance after six and twelve months. This helps you learn which methods are predictive for your organisation and which are not.
What you gain
- Fewer poor hires, and each poor hire costs, on average, half to a full annual salary.
- Decisions that you can justify to applicants, the works council, and the courts.
- Interviews that are shorter and more informative.
From our projects
When we link selection evaluations to subsequent performance after twelve months, many companies find that unstructured interviews have practically no predictive power, while work samples and structured interviews perform significantly better. The most common objection from managers is the effort involved. After the initial guides, this reverses because conversations become shorter and decisions are easier to make.
Good to know
Under § 95 BetrVG (Works Constitution Act), the works council in companies with more than 500 employees can demand the establishment of selection guidelines. Since 2021, this explicitly applies even when AI is used in their establishment. The Allgemeines Gleichbehandlungsgesetz (General Equal Treatment Act) requires that selection criteria do not relate to age, gender, origin, religion, disability, or sexual identity. Documented criteria are the best protection against compensation claims under § 15 AGG.
Frequently asked questions
Are personality tests useful?
Not for most roles. Work samples and structured interviews are better predictors of performance. Tests are worthwhile as a pre-filter when applicant numbers are high, or for roles where specific characteristics are demonstrably crucial.
Are we permitted to use AI for pre-selection?
Yes, under conditions: the criteria must be known and non-discriminatory, a human must make the decision, applicants must be informed, and the works council (Betriebsrat) must be involved. From December 2027, the high-risk obligations of the AI Act will apply.
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Further reading
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