Feeling of knowing and duration of unsuccessful memory search.

Five experiments examined the impact of feeling of knowing on decisions to continue or to terminate the search of memory in question answering. First, two pairs of experiments respectively scrutinized knowledge about (1) ordinary facts and (2) national capitals. The first experiment of each pair extracted normative data: The participants indicated whether they had probably once known the answer to a question (once-knew-it scale), supplied the answer if they knew it, and either judged the likelihood of their recognizing the answer or made other pertinent metacognitive judgments. In these norming experiments, recognition ratings were highly correlated with once-knew-it responses, and both measures were highly predictive of performance. Thisindicated that both measures reflect feeling of knowing judgments. In the second experiment of each pair, different participants were timed as they indicated whether they knew the answer to the same questions. Responselatencies for responding "don't know" were strongly positively correlated with the once-knew-it judgments made by the norming participants. This relationship was corroborated by Experiment 5, which compared the crucial measures within participants. These outcomes suggest that, in this context, feeling of knowing judgments are predictive of how long people will search memory for requested information.