The aim of the present research was to extend the earlier work of Donald Broadbent on the relationship between cognitive failures scores and the difference between performance of categoric search and focused attention tasks. Results from four experiments, involving over 400 subjects, replicated Broadbent's finding that there was a small negative correlation between level of cognitive failure and the difference in speed of responding in categoric search and focused attention choice reaction time tasks. However, consideration of correlated attributes of cognitive failure showed that this effect could be explained in terms of differences in trait anxiety. It was, however, possible to derive another measure from the tasks, which was correlated with cognitive failure but independent of anxiety. In contrast to the relationship initially described by Broadbent, the correlation between the new measure and cognitive failure proved less reliable, being modified by the different contextual factors in the various experiments.