Abstract: In this study the cognitive tactics of senior technicians in man-machine system was proposed using repertory grid method. It wasfound that: 1) In the cognitive structures of sinior technicians thereare cognitive maps which can diagnose the complex factors, andthe cognitive maps made up of breakdowns and cause characteristicswith specially designated patterns. They are crucial effects inthe training of complex skill. 2) The repertory grid, method is aneffective method in functional simulation of experts' cognitivestructures. This method not only gives new information on theexperts'heuristic tactics with its objective projection, exploring theunknown cognitive structures, but also has impressive applied pros-pects in the training and assessment of complex skill.

Key words: repertory grid method, senior technician, cognitive map, cognitive tactics, element, construct