A cognitive psychologist wanted to test whether chewing mint-flavoured gum improves focus and concentration.

The psychologist conducted a study using 12 student volunteers from a local college. The psychologist used a repeated measures design. Half of the participants started in Condition A (chewing gum) and half started in Condition B (no gum).

All participants were asked to complete a computerized visual search task where they had to find target shapes among distracting stimuli. All participants were given standardised instructions and completed the task in a quiet room on the same model of computer. The psychologist recorded the number of errors made on the visual search task during a 5-minute session. The participants returned to the laboratory three days later to repeat the task in the alternative condition.