Accuracy and Confidence of Duration Estimates Following Questions Containing Marked and Unmarked Modifiers1


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    This research was supported by a grant from the Social Sciences and Humanities Research Council of Canada. Appreciation is extended to Eva Matthys and Sharon Nicklas and to the 15 undergraduate students who volunteered to gather data.

Correspondence regarding this article should be sent to A. Daniel Yarmey, Department of Psychology, University of Guelph, Guelph, Ontario, Canada, NIG 2W1.


Eighty-five subjects were engaged in a two-person discussion for 20 minutes or for 40 minutes. Half of each group was tested immediately and the remainder one week later for their estimate of the duration of the discussion. Postevent questions were phrased with either a marked modifier (“How short was our discussion?”) or an unmarked modifier (“How long was our discussion?”), or subjects were tested using a non-leading noun-form statement (“What was the duration of our discussion?”). Sixty-seven percent of all subjects underestimated and 31% overestimated their respective durations. Accuracy of time estimation was unrelated to the length of the discussion or to the time of test. The adverb short on average produced overestimations, whereas the adverb long and the noun duration on average produced underestimations. No relationship was found between accuracy of estimation and certainty of estimation.