Rule-based behaviour

A scope virtually restricted to skill and rule-based behaviour, and hence a limited capacity for evaluating cognitive behaviour. 

Rule-based behaviour in which people select those routines, at a more or less conscious level, out of a very large inventory of possible routines built up over many years of experience. 

Rule-based behaviour At this level, the operator recognises a known situation and applies a pre-stored rule or action-pattern to handle it. The rules have been developed through experiences and may be individual or collective. We find, for example, traffic safety rules to avoid collisions when two cars are on an intersecting course. 

Rule-based behaviour is at work when the operator does not have the same level of practice at performing the required task, but has a clear knowledge of the procedures. There may be some hesitation in recalling any procedure, the procedure may not be carried out in the proper sequence, or any step may not be performed precisely. 

Rule based performance - behaviours which require more mental effort and planning because we are operating in less famiUar territory or where a skill-based approach isn t going to work. 

A further relationship exists between these error Qpes and Rasmussen s [3] classic model of skill, rule and knowledge-based behaviour. Slips and l >ses tend to occur at the skill-based level, whereas mistakes occur at the rule-based and knowledge-based levels. Rule-based mistakes are primarily due to mis lied expertise, where some pre-established plan or problem solution is lied inappropriately. Knowl ge-based mistakes generally occur due to a lack of e q)ertise, where no off-the-shelf solution exists and an individual is forced to work out a plan of action fiom first principles. 

Reason goes further and highlights the likely feilure modes at each level of behaviour. For exanq>le skill-based enors occur due to control-mode fiulures of both inattention and over-attention. Rule-based errors can arise fiom the misapplication of rules or the q>plication of incorrect rules. Knowledge-based errors can arise due to selectivity, biased reviewing and a number of other fiictors. 

A relatively simple model has been developed by Rasmussen to quantify human error rates based on the level of training (Rasmussen (1979, 1981)). This model divides the behaviour into three basic categories skill-based, rule-based, and knowledge-based behaviours. 

Determine operator behaviour - For each of the tasks identified in Step 2, determine the required operator s behaviours. Three types of behaviours are considered namely, skill-based, rule-based or knowledge-based behaviour. These behaviours are discussed in Sections 9.3. 

Dimension Errors based on automatic behaviour Rule-based Knowledge-based errors errors... 

There is no general rule as to whether or not glass reinforcement enhances the fatigue behaviour of the base material. In some cases the matrix exhibits longer fatigue endurances than the reinforced material whereas in other cases the converse is true. In most cases the fatigue endurance of grp is reduced by the presence of moisture. 

Methyl 4-[2-(ethylthiocarbonyl)ethenyl]cinnamate (3 SMe) crystallizes into a typical a-translation-type packing structure in which the distances between the ethylenic double bonds are 3.988 A and 4.067 A, respectively. However, the 3 SMe crystal is entirely photostable even though it should be photoreactive based on the topochemical rule (Sukegawa, 1991). Several examples of exceptionally photostable diolefin crystals have been found in compounds having a thioester moiety. Such anomalous behaviour of crystals such as 2 OMe and 3 SMe cannot be explained simply in terms of the topochemical rule since this rule involves only the positional relationship between the reactive olefin pair. 

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