Abstract: Dual-task performance is a basic behavior pattern in complex man-ma-chine systems.The present research is focused on the effects of the outcome conflict and task difficulty on dual-task performance.The results of the data analysis support the following conclusions:(1)The interference between information-processings of the two tasks is a major source in dual-task decrecement.The higher the interference,the worse the dual-task performance;(2)The resource competition is another major source in dual-task decrecement.The higher the competition,the worse the dual-task performance.Based on the experiment,a two-factors theory was proposed.

Key words: Dual-task performance, Outcome conflict, Task difficulty, Information interference, Resource competition