Perceived behavioural control

The theory has stimulated much research, the vast majority of which has found that the Theory of Reasoned Action strengthened the links between attitudes and behaviour. However, researchers have found other factors, not included in the original theory, that also have an influence. The first modification of the theory was suggested by one of its original formulators, Icek Ajzen. He added the concept of Perceived Behavioural Control (PBC), to create what he referred to as the Theory of Planned Behaviour (see Eagley and Chaiken, 1993). 

Perceived Behavioural Control As with attitudes and subjective norms, PBC is formed from a number of elements. In this case the elements are ... 

This approach leads to a reformulation of current situational awareness models. Endsley s sequence of perceiving, understanding and projection into the futine is turned rrpside down if the projection into the future becomes the first and leading step. In addition, we would include a loop of non-conscious, highly automated processes in a model of Arrticipatory Behaviour Control as depicted in Figure 7.1. 

The choice of specific systems where readily perceived changes of properties were associated with changes in the controlling chemical equilibrium enabled explanation in general and prediction in particular to be finked to behavioural changes. 

Kushnir, T. and Melamed, S. (1991). Workload, perceived control and psychological distress in type A/B industrial workers. Journal of Organizational Behaviour 12 155-68. 

The consequences of allowing the provision of materials and information to site to get out of hand in this fashion are usually far more severe than the consequences of initiating a controlled schedule delay. Unfortunately this is not readily perceived early enough, possibly out of optimism, more probably from collective behaviour in a climate where the acknowledgement of bad news is regarded as defeatism. 

The courts and the police, as officially designated agents of social control, had to operate in terms of a socially sanctioned role. They could not opt out of this role they had to take some action. Their action was also limited to rule enforcement, rather than the creation of new rules. The fact that these limits were often exceeded, is attributable not to their absence, but to the perceived innovatory aspects of the behaviour itself, sensitization, symbolization and the whole belief system. Rationalizations such as new situations need new remedies accoimt for those elements exclusively directed at the particular deviance being controlled. 

Brown and Noy (2000) considered several driver behaviour models in an attempt to look for variables associated with behavioural adaptation to driver support systems. One conclusion of their study was that one element that determines the degree to which humans rely on automation is the amount of trust drivers feel towards a system, which in turn depends on a system s perceived competency. One hypothesis is that in-vehicle systems that are perceived by users to be trustworthy are also those that generate behavioural adaptation. They propose that new directions in studies of behavioural adaptation should include notions as trust in automation and possible contributing psychological variables as SS and locus of control (LoC) (Brown and Noy, 2004). In follow-up studies, Rudin-Brown and Noy (2002) and Rudin-Brown (2010) proposed their qualitative model of behavioural adaptation (Figure 11.1) from which they developed hypotheses about psychological characteristics that may affect behavioural adaptation to in-vehicle intelligent transport systems (ITS). 

Overall the behavior analysis shows that user initative was more effective, as might be expected however, when the task is more difficult the difference between the patterns is less clear cut. Users appear to be more tolerant of system control if they perceive the advice may be important. Interestingly, when we examined the patterns by modality, it appeared that the agent condition had little impact on the pattern of user behaviour. 

This theory is based on the assumption that the operator is able to perceive a risk level in the environment that is related to the actual risk level through a delayed feedback. The operator adapts his or her behaviour in such a way that there is a balance between the hazards that the operator is exposed to and what he or she can accept (target level of risk). It follows from this theory that measures to reduce hazards at the workplace will be followed by changed behaviour on the part of the operators such that their perceived level of risk remains the same. The only way to improve safety is to change the operators target risk level. The risk-homeostasis theory was primarily developed for situations where people voluntarily expose themselves to accident risks such as in traffic. We must expect, however, that employees at a workplace also to some extent control the risk that they are exposed to based on their own experiences and preferences. 

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