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Assessment centre

An assessment centre is a process in which candidates are evaluated through several exercises at once, typically including simulations, group tasks, presentations and interviews, rated by multiple trained assessors against defined criteria. It is among the more thorough selection methods and among the most expensive.

A centre evaluates behaviour through multiple exercises and multiple assessors, which is where its accuracy comes from and also its cost.

Why it matters when the plan changes

Multiple exercises rated by multiple assessors reduce the influence of any single observation, which is the main source of error in one-to-one selection, a process that personnel selection literature describes as methodical rather than incidental (Personnel selection, Wikipedia, 2026). That design is why the method predicts relatively well: an assessment centre examines candidates through several techniques, including interviews and group exercises, rather than one (Assessment centre, Wikipedia, 2026). It also explains why it is reserved for senior or high-volume hiring, since the cost per candidate is substantial.

The tension is the same one that affects every selection method: the centre is rigorous about whatever criteria it was given. Exercises are built from a specification of the role, and a specification written for the previous version of the job produces a thorough, well-rated assessment of the wrong thing. Assessment data is signal, not a finished decision; connecting it to what the role now requires is a separate act of judgement that the exercises themselves cannot supply.

In practice

A centre is designed around exercises drawn from a role profile written three years earlier. Candidates are assessed carefully by four trained assessors against those criteria. The role has since changed to require cross-boundary negotiation that none of the exercises simulates, and the process ranks candidates accurately on capabilities the job no longer centres on.

Evidence

What it cannot tell you

An assessment centre tells you how a candidate behaves in the exercises built for it, not how they will perform against a role that has since changed. It is silent on capabilities the exercises were never designed to simulate, and a well run process can still rank candidates accurately on the wrong criteria.

Questions

Candidates are examined across several exercises, including simulations, group tasks, presentations and interviews, a design captured in the standard description of the method as a process where candidates are examined to determine their suitability for specific types of employment (Assessment centre, Wikipedia, 2026). Trained assessors rate independently, then reconcile ratings in structured discussion.

Because multiple exercises and multiple assessors dilute the influence of any single observation or any one assessor's impression. Error that would dominate a one-to-one conversation is averaged down, which is a structural advantage rather than a matter of assessor skill.

The main weaknesses are cost, which limits use to senior or high-volume hiring; the artificiality of simulations relative to the real job; and total dependence on the criteria. Personnel selection is described as a methodical process (Personnel selection, Wikipedia, 2026), and an outdated role specification produces a thorough assessment of the wrong capability.

Yes, as development centres, where the output goes to the participant rather than a selection decision. The design is broadly similar and the stakes differ substantially, which changes how candidates behave and usually makes the observations rather more representative of ordinary work.

As evidence about observed behaviour in specified conditions, read against what the role will actually demand, alongside other signals. Not as a ranking to be applied directly, and not for a purpose the exercises were never designed or validated to inform.