Human Decision-Making

Decision-making is a subset of our information processing capabilities. To make decisions we draw upon our sensory inputs, either externally or internally generated. We also draw upon our workbench of working memory to process these stimuli and to access long-term memory for prior experience and knowledge.

We make many thousands of decisions each day—most of which we are not aware of making. At our desks, we may shift position in response to an internal stimulus of discomfort or we may decide to go to lunch because of internal hunger pangs. In response to external stimuli, we may answer a ringing telephone or respond to a request from a coworker.

The decisions of which we are most aware are those on which we expend time and effort contemplating. These typically involve planning and weighing the outcomes of several alternatives. In a work setting, this may include deciding the next step in a task, evaluating results and making recommendations, or planning work products for the next year. In our personal lives, examples may include choosing a car to purchase, where to go on a vacation, or a school for our children.

How humans make decisions has been a documented topic of interest since the time of Aristotle. It has significant implications for everything ranging from our personal lives and work performance, to society as whole in national policy making, economics, and social welfare. In human factors, it impacts how human-to-system interfaces and decision support systems are best designed to aid efficient, error-free human decisions.

Optimization Under Constraints

Other theories recognized the constraints of information search to support decision-making. Whether the search was internal through one's memory or whether the search was in the external environment by seeking knowledge from experts, friends, libraries or other sources--it takes time! Therefore, there must be realistic stopping rules for when sufficient search has been done, and one must get on with making the decision.*

The stopping rule for Optimization Under Constraints decision theory was to stop search when the costs of searching outweighed the benefits. Costs include time expenditure, money, or any other resources. The flaw in this theory is that Unbounded Rationality again seeps in with the assumption that humans have unlimited time, knowledge, and computational power with which to compute the cost benefits at each step in information search. This is not how humans actually make decisions.*

Heuristics and Biases

To address how humans make decisions in the real world, a psychological theory arose in the 1970's that was termed Heuristics and Biases. This theory recognized that humans use simple rules or short-cuts for decision making, usually based on prior experience. However, instead of pointing out the utility of heuristics in real world decision making, this theory stressed the negative aspects of "rule-of-thumb" use. Heuristics and Biases theory contended that heuristics can result in systematic errors, as well as, lapses in reasoning and demonstrate human irrationality and fallibility. Again, the measure of human rationality and sound decision making was whether or not the laws of probability were followed. The resulting view of humans was one of irrational creatures who could not cope with the complexities of the real-world.*

Other theorists took a much more optimistic view of human-decision making and the use of heuristics. After all, human mental processes were well adapted to the real world environment with which human must interact. Why should decision-making be different? These theorists were interested in more "Naturalistic Decision-Making."

Decision Aids

While recent research has shown fast and frugal heuristics to be an accurate and viable means for everyday decision making, this does not preclude the use of probabilistic decision-making for complex issues. However, the limitations of human information processing dictates that when probabilistic methods are used, humans require the use of decision aids. In the same vein as using paper and pencil to extend working memory in solving mathematical problems, computer programs can be used to support probabilistic decision-making. These programs keep track of human-developed criteria, apply human-assigned weights, and perform the complex computations required.

In fulfillment of Simon's vision for using computer "intelligence" to assist human decision-making, computer simulation is widely used to assist in human-to-system interface design and even to model human participation in complex systems. Computer simulation has become a powerful engineering tool to evaluate system concepts prior to design and build.

Heuristics are how we make everyday decisions. However, care also needs to be taken in this regard. While the usefulness of heuristics has been proven for a variety of decisions such as stock selection, one needs to be on-guard for biases and prejudices that can creep into heuristic decisions. This is particularly a concern when decisions are "people-related."

Summary

This module presented the basics of human memory and information processing. The three basic memory components were introduced: sensory, short-term/working, and long-term. The strengths and limitations of each were described as well as the three basic memory processes: encoding, maintenance, retrieval. Christopher Wickens' memory model was used to elaborate on these basic components and processes and to emphasize the importance of attention resources in task performance.

The importance of taking into account attention resources in human-to-system interface design was discussed. Specially covered was the need to focus the user's attention on information supportive of task performance while reducing distractions and attention-competing information sources. In addition, the limitations of working memory, our mental workbench, was presented with attendant recommendations for memory aids. Also included were memory encoding techniques and long-term memory storage and retrieval.

The section on decision making set forth the most prevalent theories of how humans make decisions in everyday life and how computers can aid more complex decision making. The final part of the module covered some workload assessment techniques. These techniques are used to evaluate cognitive load in task performance with the goal of designing interfaces and tasks that neither bore nor overload the human user.

Source : http://www.hf.faa.gov/Webtraining/Cognition/CogFinal048.htm