Human information processors

The second objective is that human-centered design should help overcome human limitations. This requires that limitations be identified and appropriate compensatory mechanisms be devised. A good illustration of a human limitation is the prochvity to meike errors. Humans are fairly flexible information processors, but this flexibility can lead to innovations that are erroneous in the sense that undesirable consequences are likely to occur. 

Processor One of two major subsystems types within the human information-processing system that performs the general function of processing information. Multiple processors at different hierarchical levels can be identified (e.g., those specific to sensory modalities, integrative processors, etc.). 

Model human processor (HMP) Models human information processing in terms of processing subsystems, memories, and performance parameters Performance is modeled by assigning time values to the modePs parameters Perceptual, Long-term and working memories... 

Barron, S. and Kleinman, D.L. 1969. The human as an optimal controller and information processor. IEEE Trans. Man-Mach. Syst. MMS-10 9. 

In considering the performance of human information-processing systems, the resource-based perspective represented by the Elemental Resource Model (Kondraske, 2000) is adopted here. This model for human performance encompasses all types of human subsystems and is the result of the application of a general theoretical framework for system performance to the human system and its subsystems. A central idea incorporated in this framework, universal to all types of systems, is that of performance capacity. This implies a finite availability of some quantity that thereby limits performance. A general two-part approach is used to identify unique performance capacities (e.g., visual information processor speedy. (1) identify the system (e.g., visual information processor) and (2) identify the dimension of performance (e.g., speed). In this framework, system performance capacities are characterized by availability of performance resources along each of the identified dimensions. These performance resources... 

Human information-processing models focus on the interaction between the human operator and the environment in a disturbed system. This interaction is analysed from the human operator s point of view. The operator is viewed as an information processor who responds to deviations and hazards in the environment, Figure5.10.Inananalysisofan accident, the aim is to identify human failures in identifying and evaluating the situation and in taking the appropriate measures. 

Figure 5.10 is a typical outcome of the research into human perception and cognition that made great progress in the 1960s. The human operator was viewed as an information processor that is exposed to a demanding environment. Accidents result mainly from the human operator s inability to handle the information in complicated situations. We will come back to other theories and models of human behaviour in accident situations in Chapter 8. There we will see how other theories and models have substituted... 

Kjellen (2010) sheds fight on human and environment interaction from an operator s point of view. Under this model, people are viewed as an information processor who makes their own judgment in response to environment risks,... 

From the 1960s onward, there was a greater interest in psychological issues, dominated by the concept of the human as a single-channel processor of information. This stimulated research into a number of areas. Studies of mental workload were concerned with the ability of humans to cope with extremely high levels of information in situations such as air traffic control. Vigilance studies, which focused on the human s role in situations with very low levels of stimulation such as radar monitoring, represented the other extreme of human performance that was considered. 

Machine vision systems tend to mimic the human vision system. An optical sensor and electronic main processor typically act as the eyes and brain and, as in humans, they work together to interpret visual information. Also like their human counterparts, the sensor and processor are each somewhat responsible for filtering out the useless information within the scene before it is analyzed. This reduces the overall processing requirements and allows humans and well-designed machine vision systems to make decisions based on visual information very quickly. 

As stated by Scott (1984), published information on mycotoxins in foods processed for human consumption is limited. Information on the extent that mycotoxins persist through processing is important for risk management by food processors and regulatory authorities. Whereas past research mainly focused on cereal processing, this chapter summarizes available literature on major categories of fruit products dried fruits, fruit juices, wine and cider as fermented fruit juices, and fruit purees and jams. 

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