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title: 10 Instrument: work samples as written work probes
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# 10 Instrument: work samples as written work probes

The third format is the work sample, implemented as a written work probe: a short, representative task whose output can be completed digitally – a project plan, a case response, a memo, a piece of analysis – scored against task-specific criteria derived from the requirement.

The research basis is the work-sample category in Sackett et al. \[3\]: a corrected operational validity of .33, down from .54 in the older estimates, which still places it among the stronger job-specific predictors, and a Black–White standardised mean difference of .67 – the largest of the three formats in this concept, and the reason the probe needs the closest fairness check of the three.

Sackett et al. \[4\] add two cautions that shape its use: work samples are less applicable to entry-level hiring where the relevant skills are learned after hire, and the credibility interval around the mean matters as much as the mean. A probe is therefore not a default; it is chosen per requirement where demonstrated performance is the evidence that matters and where the task can be representative of the work.

Methodologically the probe is the clearest case of the method definition in section 3.2: evidence collection is the task, the scoring guide is the criteria sheet, and validity belongs to that pair in use.

Specification names the task, the allowed tools and time, the language and the criteria with their levels; research support cites the work-sample literature and its limits of transfer to a written, unsupervised format; predictive validity is evaluated locally as for the other formats; bias and fairness cover access to tools and time, language, and the group difference the literature reports; scoring consistency is agreement between qualified assessors and between the AI criteria scoring and reviewers; efficiency weighs the higher candidate effort against the information gained – a probe is used only where it adds information the passport and the questions do not give.

The existing evaluation pipeline is reused: the evaluator judges each criterion of the sheet, the scoring model produces a level, the summariser cites the submission, and the submission itself stays attached as evidence rather than being rewritten. What has to be built new is the task bank per role family with its criteria sheets, the candidate-facing delivery with time and tool rules, and the validation that a probe's criteria scoring behaves like the question scoring does today. In the extended model the probe level sits beside the passport and question levels on the scorecard; a requirement such as "plan projects with milestones" can carry all three, and the reviewer sees where they agree and where they do not.

![Figure 22 – Why a taxonomy-based system makes bias measurable and tunable.](../media/image22.png)

*Figure 22 – Why a taxonomy-based system makes bias measurable and tunable.*