Donald G. MacGregor

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Forecasters often need to estimate uncertain quantities, but with limited time and resources. Decomposition is a method for dealing with such problems by breaking down (decomposing) the estimation task down into a set of components that can be more readily estimated, and then combining the component estimates to produce a target estimate. Estimators can(More)
InT. Gilovich, D. Griffin, & D. Kahneman (Eds.), Heuristics and biases: The psychology of intuitive judgment (pp. 397-420). New York: Cambridge University Press,2002. This chapter introduces a theoretical framework that describes the importance of affect in guiding judgments and decisions. As used here,. affect means the specific quality of "goodness" or(More)
Modern theories in cognitive psychology and neuroscience indicate that there are two fundamental ways in which human beings comprehend risk. The "analytic system" uses algorithms and normative rules, such as probability calculus, formal logic, and risk assessment. It is relatively slow, effortful, and requires conscious control. The "experiential system" is(More)
This article describes studies designed to inform policy makers and practitioners about factors influencing the validity of violence risk assessment and risk communication. Forensic psychologists and psychiatrists were shown case summaries of patients hospitalized with mental disorder and were asked to judge the likelihood that the patient would harm(More)
This paper is a revised version of a chapter titled “The Affect Heuristic,” by Paul Slovic, Melissa Finucane, Ellen Peters, and Donald G. MacGregor, published in T. Gilovich, D. Griffin, & D. Kahneman, (Eds.), Heuristics and Biases: The Psychology of Intuitive Judgment. Cambridge University Press, 2002, pp. 397-420. An earlier version of this paper was(More)
Risk is perceived and acted on in 2 fundamental ways. Risk as feelings refers to individuals' fast, instinctive, and intuitive reactions to danger. Risk as analysis brings logic, reason, and scientific deliberation to bear on risk management. Reliance on risk as feelings is described with "the affect heuristic." The authors trace the development of this(More)
When people learn a complex skill like computer text editing they are learning a set of goals and the plans for accomplishing those goals. In this experiment we examined the structure and development of simple text-editing goals and plans. Long interkeystroke times were found to be associated with plan boundaries. The longest times were found between(More)
Traditional theories of finance posit that the pricing of securities in financial markets should be done according to the quality of their underlying technical fundamentals. However, research on financial markets has tended to indicate that factors other than technical fundamentals are often used by market participants to gauge the value of securities. This(More)
The perception of the potential risk arising from human exposure to 50/60 Hz electric and magnetic fields was studied with a quasi-random sample of 116 well-educated, opinion leaders using the risk perception framework previously developed by Slovic, Fischhoff, and Lichtenstein. These individuals rated exposure to fields from transmission lines and electric(More)
Steep declines in the value of publicly traded stocks in the first quarter of 2001 left many market observers speculating whether investor sentiment had undergone a significant and negative change, and whether investors would subsequently flee stocks in favor of less volatile investment options. A survey study of investor expectations and confidence was(More)