Technique and experimental design
Probe how they design studies: within versus between subjects, counterbalancing, sample sizing, and instruments such as SUS, NASA-TLX, think-aloud protocols, eye tracking or Tobii heatmap setups.
Evidence to listen for
- Runs the assays and instruments themselves rather than describing what a team does
- Designs experiments with controls, replicates, and a stated hypothesis
- Knows what each technique can and cannot resolve
- Understands the science, not only the protocol
Five-point scoring guide
Protocol follower with no experimental design; cannot justify controls.
Runs standard assays; designs experiments poorly or not at all.
Competent at the bench with sound routine design.
Designs rigorous experiments and understands the limits of each technique.
Names the study design and rationale, defends sample size and task order, and distinguishes formative usability work from controlled comparative experiments.