Neville A. Stanton

Perspectives on safety culture

Overviewing selected elements from the literature, this paper locates the notion of safety culture within its parent concept of organisational culture. A distinction is drawn between functionalist and interpretive perspectives on organisational culture. The terms ‘culture’ and ‘climate’ are clarified as they are typically applied to organisations and to safety. A contrast is drawn between strategic top down and data-driven bottom up approaches to human factors as an illustrative aspect of safety. A safety case study is used to illustrate two measurement approaches. Key issues for future study include valid measurement of safety culture and developing methods to adequately represent mechanisms through which safety culture might influence, and be influenced by, other safety factors.

Distributed situation awareness in dynamic systems: theoretical development and application of an ergonomics methodology

The purpose of this paper is to propose foundations for a theory of situation awareness based on the analysis of interactions between agents (i.e. both human and non-human) in subsystems. This approach may help to promote a better understanding of technology-mediated interaction in systems, as well as helping in the formulation of hypotheses and predictions concerning distributed situation awareness. It is proposed that agents within a system each hold their own situation awareness, which may be very different from (although compatible with) that of other agents. It is argued that we should not always hope for, or indeed want, sharing of this awareness, as different system agents have different purposes. This view marks situation awareness as a dynamic and collaborative process binding agents together on tasks on a moment-by-moment basis. Implications of this viewpoint for the development of a new theory of, and accompanying methodology for, distributed situation awareness are offered.

What really is going on? Review of situation awareness models for individuals and teams

The concept of situation awareness (SA) is frequently described in the literature. Theoretically, it remains predominantly an individual construct and the majority of the models presented describe SA from an individual perspective. In comparison, team SA has received less attention. SA in complex, collaborative environments thus remains a challenge for the human factors community, both in relation to the development of theoretical perspectives and of valid measures and to the development of guidelines for system, training and procedure design. This article presents a review and critique of what is currently known about SA and team SA, including a comparison of the most prominent individual and team models presented in the literature. In conclusion, it is argued that recently proposed systems level distributed SA approaches are the most suited to describing and assessing SA in real world, collaborative environments.

The Design with Intent Method: A design tool for influencing user behaviour

Using product and system design to influence user behaviour offers potential for improving performance and reducing user error, yet little guidance is available at the concept generation stage for design teams briefed with influencing user behaviour. This article presents the Design with Intent Method, an innovation tool for designers working in this area, illustrated via application to an everyday human-technology interaction problem: reducing the likelihood of a customer leaving his or her card in an automatic teller machine. The example application results in a range of feasible design concepts which are comparable to existing developments in ATM design, demonstrating that the method has potential for development and application as part of a user-centred design process.

Malleable attentional resources theory: A new explanation for the effects of mental underload on performance

This paper proposes a new theory to account for the effects of underload on performance. Malleable attentional resources theory posits that attentional capacity can change size in response to changes in task demands. As such, the performance decrements associated with mental underload can be explained by a lack of appropriate attentional resources. These proposals were explored in a driving simulator experiment. Vehicle automation was manipulated at 4 levels, and mental workload was assessed with a secondary task. Eye movements were also recorded to determine whether attentional capacity varied with mental workload. The results showed a clear decrease in mental workload associated with some levels of automation. Most striking, though, were the results derived from the eye movement recordings, which demonstrated that attentional capacity varies directly with level of mental workload. These data fully supported the predictions of the new theory. Malleable attentional resources theory suggests that future vehicle designers should employ their technology in driver support systems rather than in automation to replace the driver. The implications of this theory are discussed with regard to capacity models of attention as well as to the design of future vehicle systems.

Situational awareness and safety

This paper considers the applicability of situation awareness concepts to safety in the control of complex systems. Much of the research to date has been conducted in aviation, which has obvious safety implications. It is argued that the concepts could be extended to other safety critical domains. The paper presents three theories of situational awareness: the three-level model, the interactive sub-systems approach, and the perceptual cycle. The difference between these theories is the extent to which they emphasise process or product as indicative of situational awareness. Some data from other studies are discussed to consider the negative effects of losing situational awareness, as this has serious safety implications. Finally, the application of situational awareness to system design, and training are presented.

Drive-by-wire : The case of driver workload and reclaiming control with adaptive cruise control

Vehicle automation is highly likely to be in service by the end of this century. Whilst there are undoubtedly some benefits associated with such systems, there are some concerns also. This paper presents work in progress on the Southampton Driver Simulator on driver workload and the drivers ability to reclaim control from the Adaptive Cruise Control system in a malignant scenario. Previous studies suggest that there may be some cause for concern. This study shows a reduction in mental workload, within a secondary task paradigm, associated with operating Adaptive Cruise Control. This finding is contrary to previous research into Adaptive Cruise Control. Further, in line with other research, this study shows that a third of the participants were unsuccessful in reclaiming control of the vehicle before a collision occurred. We suggest that more research and development effort needs to be spent on looking at the communication between Adaptive Cruise Control and the driver.

Driver behaviour with adaptive cruise control

This paper reports on the evaluation of adaptive cruise control (ACC) from a psychological perspective. It was anticipated that ACC would have an effect upon the psychology of driving, i.e. make the driver feel like they have less control, reduce the level of trust in the vehicle, make drivers less situationally aware, but workload might be reduced and driving might be less stressful. Drivers were asked to drive in a driving simulator under manual and ACC conditions. Analysis of variance techniques were used to determine the effects of workload (i.e. amount of traffic) and feedback (i.e. degree of information from the ACC system) on the psychological variables measured (i.e. locus of control, trust, workload, stress, mental models and situation awareness). The results showed that: locus of control and trust were unaffected by ACC, whereas situation awareness, workload and stress were reduced by ACC. Ways of improving situation awareness could include cues to help the driver predict vehicle trajectory and identify conflicts.

Vehicle automation and driving performance

Vehicle automation is highly likely to be in service by the end of this century. While there are undoubtedly some benefits associated with such systems, there are some concerns also. This paper presents a review of studies addressing adaptive cruise control and active steering systems. These studies suggest that there may be some cause for concern. They show a reduction in mental workload, within a secondary task paradigm, associated with some forms of automation and some problems with reclaiming control of the vehicle in failure scenarios. It is suggested that more research and development effort needs to be spent on looking at vehicle automation and driving performance.

A review of sociotechnical systems theory: a classic concept for new command and control paradigms

Command and control is the management infrastructure for any large, complex, dynamic resource system (Harris, C.J. and White, I., 1987. Advances in command, control and communication systems. London: Peregrinus). Traditional military command and control is increasingly challenged by a host of modern problems, namely, environmental complexity, dynamism, new technology and competition that is able to exploit the weaknesses of an organisational paradigm that has been dominant since the industrial revolution. The conceptual response to these challenges is a new type of command and control organisation called Network Enabled Capability (NEC). Although developed independently, NEC exhibits a high degree of overlap with concepts derived from sociotechnical systems theory, a fact that this paper aims to explore more fully. Uniquely, what sociotechnical theory brings to NEC research is a successful 50 year legacy in the application of open systems principles to commercial organisations. This track record is something that NEC research currently lacks. The paper reviews the twin concepts of NEC and sociotechnical systems theory, the underlying motivation behind the adoption of open systems thinking, a review of classic sociotechnical studies and the current state of the art. It is argued that ‘classic’ sociotechnical systems theory has much to offer ‘new’ command and control paradigms. The principles of sociotechnical systems theory align it exceptionally well with the challenges of modern organisational design. It is also reflective of a wider paradigm shift in ergonomics theory away from ‘industrial age’ modes of thought to systems-based ‘information age’ thinking.