A discrete user reaction of surprise or astonishment occurring when an AI system produces output that exceeds the user's prior expectation of its capability. The reaction is a property of the human appraisal, not of the system.
EVENT. Counted once per transcript turn in which the user explicitly marks unexpected capability (e.g. 'I didn't expect that', 'wow', 'how did it do that') OR, in think-aloud studies, verbalises surprise within 5 seconds of receiving output. Repeated markers about the same output count as one event.
Proposed measurement protocol (not yet empirically validated): Rater-coded count of surprise-marked turns per session; two independent coders, inter-rater reliability could be reported as Cohen's kappa. Optionally corroborated by a single post-task item ('How surprising was the system's performance?', 1-7).
https://andreasehstandlicenseofclarityloc.github.io/augmanitai-periodic/#topic-emotion-affect