Effects of training on short- and long-term skill retention in a complex multiple-task environment

The paper reports the results of an experiment on the performance and reten tion of a complex task. This was a computer-based simulation of the essenti al elements of a spacecraft's life support system. It allowed the authors t o take a range of measures, including primary and secondary task performanc e, system intervention and information sampling strategies, mental model st ructure, and subjective operator state. The study compared the effectivenes s of two methods of training, based on low level (procedure-based) and high level (system-based) understanding. Twenty-five participants were trained extensively on the task, then given a 1-h testing session. A second testing session was carried out 8 months after the first (with no intervening prac tice) with 17 of the original participants. While training had little effec t on control performance, there were considerable effects on system managem ent strategies, as well as in structure of operator's mental model. In the second testing session, the anticipated general performance decrement did n ot occur, though for complex faults there was an increase in selectivity to wards the primary control task. The relevance of the findings for training and skill retention in real work environments is discussed in the context o f a model of compensatory control.