Abstract
Wason’s selection task shows people test a rule by looking for the instance that fits it rather than for the case that would break it.
Wason, P. C. (1968). Quarterly Journal of Experimental Psychology, 20(3), 273–281. DOI
Key findings
- Confirming search — The first test people run is the instance that matches the rule.
- Disconfirm unused — The card that could falsify the rule is systematically left unturned.
Limits
Cite-anchor shelf — closed access; expand after a full read. The laboratory selection task is a narrow paradigm — life-story application belongs to the later review family, not this 1968 experiment.
Application
When you schedule only the rooms that already fit the story, name the unscheduled counter-example before you file the result as proof (Confirmation bias).