Institute of Psychology, the Russian Academy of Sciences, Moscow, Russia
Background. The relationships between conceptual model structures and an operator’s professional efficiency are of direct practical importance, particularly in the case of large-scale industrial complexes combining several human-machine systems. A typical example is the power unit of a nuclear power plant (NPP).
Objective and methods. The purpose of this study was to explore the conceptual models of senior reactor operators (SROs) of NPPs. The study involved 64 men working as SRO at five NPPs in Russia. The methods included: structured interviews, expert estimations, multidimensional scaling (ALSCAL), the K-means clustering algorithm, and frequency analysis. The procedure was as follows: 32 key characteristics of the power unit were defined, including shift operators’ jobs and duties, technical subsystems, types of equipment, and the crucial power unit parameters. The participants were offered a 32×32 matrix for pair-wise estimation of the strength of the links between these key characteristics on a seven-point scale (496 links in total).
Results. A general scheme of key characteristics in the conceptual models was defined. is scheme was displayed in the operators regardless of their employment history. Within the scheme, however, two types of conceptual models were identified, which could be distinguished by the relative number of strong links between the key characteristics. With respect to intersystem links including key characteristics of the reactor and turbine NPP departments, this number was significantly higher in models of Type 1 than in those of Type 2. A positive correlation between the number of these links and the professional efficiency indicators was also established. Operators with Type 1 models were able to more predictably represent the power unit operation.
Conclusion. The main role in creating predictable and efficient conceptual models was played by strong intersystem links in mental representations of workflow.
Keywords: Nuclear Power Plant (NPP) senior reactor operator (SRO), conceptual model, mental image, multidimensional scaling, workflow, subjective strength of links, professional efficiency