Effects of accessible information amount and judgment times on human diagnostic performance of nuclear power plant faults

Information is key to the process of diagnosis, so it is necessary to understand how information amount may influence human performance. The current study investigated this issue through an experiment where participants diagnosed an accident in a simulated nuclear power plant. The amount of accessible information and the times of making judgments were manipulated. The results showed that increasing the amount of accessible information led the participants to seek more and think shallower, and thus decreased diagnostic accuracies, whereas no significant effects were found for multiple judgement times. The authors argue that the disadvantages of more accessible information could be attributed not simply to 'information overload', but partly to the diagnosticians' unwise choice of information processing strategies. The findings imply that system designers should restrain the ever-growing amount of information while users should make more efficient use of information rather than take in more. Practitioner summary: Current research on diagnosis by humans was mostly limited to outcome performance. This study empirically investigated factors influencing its detailed process. The results showed that increasing accessible information amount impaired both process and outcome performances.