Operator monitoring in a complex dynamic work environment: a qualitative cognitive model based on field observations

Complex and dynamic work environments provide a challenging litmus-test with which to evaluate basic and applied theories of cognition. In this work, we were interested in obtaining a better understanding of dynamic decision making by studying how human operators monitored a nuclear power plant during normal operations. Interviews and observations were conducted in situ at three different power plants to enhance the generalizability of results across both individuals and plants. A total of 38 operators were observed for approximately 288 hours, providing an extensive database of qualitative data. Based on these empirical observations, a cognitive model of operator monitoring was developed. This qualitative model has important theoretical implications because it integrates findings from several theoretical perspectives. There is a strong human information processing component in that operators rely extensively on active knowledge-driven monitoring rather than passively reacting to changes after they occur, but there is also a strong distributed cognition component in that operators rely extensively on the external representations to offload cognitive demands. In some cases, they even go so far as to actively shape that environment to make it easier to exploit environmental regularities, almost playing the role of designers. Finally, expert operators use workload regulation strategies, allowing them to prioritize tasks so that they avoid situations that are likely to lead to monitoring errors. These meta-cognitive processes have not received much attention in the human information processing and distributed cognition perspectives, although they have been studied by European psychologists who have studied cognition in complex work environments. Collectively, these findings shed light on dynamic decision making but they also serve an important theoretical function by integrating findings from different theoretical perspectives into one common framework.