Scholars' Bank :: Browsing by Author "Fischhoff, Baruch"

Browsing by Author "Fischhoff, Baruch"

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Open Access
Accident probabilities and seat belt usage: A psychological perspective
(Accident Analysis and Prevention, 1978) Slovic, Paul; Fischhoff, Baruch; Lichtenstein, Sarah
Motorists' reluctance to wear seat belts is examined in light of research showing (a) that protective behavior is influenced more by the probability of a hazard than by the magnitude of its consequences and (b) that people are not inclined to protect themselves voluntarily against very low probability threats. It is argued that the probability of death or injury on any single auto trip may be too low to incite a motorist's concern. Maintenance of a "single trip" perspective makes it unlikely that seat belts will be used. Change of perspective, towards consideration of the risks faced during a lifetime of driving, may increase the perceived probabilities of injury and death and, therefore, induce more people to wear seat belts.
Open Access
Behavioral decision theory
(1977) Slovic, Paul; Lichtenstein, Sarah; Fischhoff, Baruch
Open Access
Behavioral decision theory perspectives on protective behavior
(Cambridge University, 1987) Slovic, Paul; Fischhoff, Baruch; Lichtenstein, Sarah
Open Access
Categorical Confidence
(Decision Research, 1983-04) Fischhoff, Baruch; MacGregor, Donald G.; Lichtenstein, Sarah
People tend to be inadequately sensitive to the extent of their own knowledge. This insensitivity typically emerges as overconfidence. That is, people's assessments of the probability of having answered questions correctly are typically too high compared to the portion of questions they get right. Few debiasing procedures have proven effective against this problem. Those that have worked seem to be directive in character. Rather than improving subjects' feeling for how much they know, such procedures may have suggested to subjects how their probability assessments should be changed. These successful manipulations include giving feedback and requiring subjects to provide reasons contradicting their chosen answers. The present study attempted to improve the appropriateness of confidence with a nondirective method. Subjects were asked to sort items into a specified number of piles according to their confidence in the correctness of their answers. Subsequently, they assigned a number to each pile expressing the probability that each item in the pile was correct. It emphasizes confidence assessment over fact assessment; it forces the comparison of knowledge levels for different questions, it deemphasizes the need to produce numbers; it gives different hints as to the fineness of the discrimination that assessors can make. This procedure differed from its predecessors in many respects; nonetheless, performance here was indistinguishable from that observed elsewhere. Although some small pockets of improvement were noted, confidence was largely resistant to this manipulation. Such robustness is discouraging for the developer of elicitation procedures, encouraging for the student of judgmental processes.
Open Access
A comparative analysis of risk perception in Hungary and the United States
(1986) Slovic, Paul; Fischhoff, Baruch; Englander, Tibor; Farago, Klara
Studies of risk perception attempt to determine how people characterize and evaluate the hazards of daily life. In the present study, questionnaires that have been used to study risk perception in the United States were translated and administered in Hungary, a country with a different hazard ecology and with different social and political processes for managing risks. Although Hungarians were found to classify hazards in ways similar to Americans on qualities such as catastrophic potential, knowability, and dread, there were strong differences in the level of perceived risk. Americans saw a greater degree of risk than Hungarians for 84 out 90 hazards that were studied. There were also systematic differences between Hungarian and American respondents in the ordering of risks. The Americans were most concerned about the risks from new, high technology hazards associated with the use of radiation and chemicals. In contrast, Hungarians were relatively more concerned about common, everyday hazards such as those associated with cars, trains, electric appliances, home gas furnaces, and childbirth. The social and psychological implications of these results are discussed.
Open Access
Cross-sectional validation of the PROMIS-Preference scoring system
(Public Library of Science, 2018-07-31) Hanmer, Janel; Dewitt, Barry; Yu, Lan; Tsevat, Joel; Roberts, Mark; Revicki, Dennis; Pilkonis, Paul A.; Hess, Rachel; Hays, Ron D.; Fischhoff, Baruch; Feeny, David; Condon, David; Cella, David
Objectives The PROMIS-Preference (PROPr) score is a recently developed summary score for the Patient-Reported Outcomes Measurement Information System (PROMIS). PROPr is a preference-based scoring system for seven PROMIS domains created using multiplicative multi-attribute utility theory. It serves as a generic, societal, preference-based summary scoring system of health-related quality of life. This manuscript evaluates construct validity of PROPr in two large samples from the US general population. Methods We utilized 2 online panel surveys, the PROPr Estimation Survey and the Profiles-Health Utilities Index (HUI) Survey. Both included the PROPr measure, patient demographic information, self-reported chronic conditions, and other preference-based summary scores: the EuroQol-5D (EQ-5D-5L) and HUI in the PROPr Estimation Survey and the HUI in the Profiles-HUI Survey. The HUI was scored as both the Mark 2 and the Mark 3. Known-groups validity was evaluated using age- and gender-stratified mean scores and health condition impact estimates. Condition impact estimates were created using ordinary least squares regression in which a summary score was regressed on age, gender, and a single health condition. The coefficient for the health condition is the estimated effect on the preference score of having a condition vs. not having it. Convergent validity was evaluated using Pearson correlations between PROPr and other summary scores. Results The sample consisted of 983 respondents from the PROPr Estimation Survey and 3,000 from the Profiles-HUI survey. Age- and gender-stratified mean PROPr scores were lower than EQ-5D and HUI scores, with fewer subjects having scores corresponding to perfect health on the PROPr. In the PROPr Estimation survey, all 11 condition impact estimates were statistically significant using PROPr, 8 were statistically significant by the EQ-5D, 7 were statistically significant by HUI Mark 2, and 9 were statistically significant by HUI Mark 3. In the Profiles-HUI survey, all 21 condition impact estimates were statistically significant using summary scores from all three scoring systems. In these samples, the correlations between PROPr and the other summary measures ranged from 0.67 to 0.70. Conclusions These results provide evidence of construct validity for PROPr using samples from the US general population.
Open Access
Cue-How safe is safe enough?
(1983) Slovic, Paul; Fischhoff, Baruch
Open Access
Decision making
(Wiley, 1988) Slovic, Paul; Lichtenstein, Sarah; Fischhoff, Baruch
Open Access
Discounting in Multicausal Attribution: The Principle of Minimal Causation
(Decision Research, 1977) Fischhoff, Baruch; Shaklee, Harriet
A series of three experiments investigated the effect of information about one possible cause of an event on inferences regarding another possible cause. Experiment 1 showed that the presence of a second possible cause had no effect on the perceived probability that the first possible cause influenced the event. However, if the second cause is cited as having definitely influenced the event, then the probability that the first possible cause influenced the event is reduced. Experiment 2 showed that the presence of a second possible cause does reduce the judged probability that a given cause was present at the time of an event. The final experiment revealed that the tendency (found in Experiment 1) to discount the involvement of the first cause given the involvement of a second cause diminishes when subjects were more highly motivated and confronted with their own discounting. These results are inconsistent with Kelley's account of discounting and provide some support for a proposed explanatory heuristic, the principle of minimal causation. Users of this principle analyze a situation until they have identified a minimal set of sufficient causes; other possible causes are ignored or dismissed.
Open Access
The Evolution of Command and Control Systems
(Decision Research, 1986-04) Fischhoff, Baruch; Johnson, Stephen
Complex technical systems go through a series of stages in their evolution from a concept of how to meet a possible challenge to an operational version responding to real-world crises. The present analysis offers a characterization of these stages and the factors that shape the transitions between them. It can be used to describe the status of a system, to characterize or antic~pate developmental difficulties, and to diagnose the sources of disagreements among those involved with it. It is illustrated here in the context of a specific system for which all stages must be addressed successfully, the National Command Authority for control of nuclear weapons in the U.S. or U.S.S.R.
Open Access
Facts and fears: Understanding perceived risk
(Plenum, 1980-08-08) Slovic, Paul; Fischhoff, Baruch; Lichtenstein, Sarah
Open Access
Images of disaster: Perception and acceptance of risks from nuclear power
(1979) Slovic, Paul; Lichtenstein, Sarah; Fischhoff, Baruch
Open Access
Informing people about risk
(1980) Slovic, Paul; Lichtenstein, Sarah; Fischhoff, Baruch
Designers of programs for informing the public about radiation hazards need to consider the difficulties inherent in communicating highly technical information about risk. To be effective, information campaigns must be buttressed by empirical research aimed at determining what people know, what they want to know, and how best to convey that information. Drawing upon studies of risk perception, this paper describes some of the problems that any information program must confront.
Open Access
Judged frequency of lethal events
(1978) Slovic, Paul; Lichtenstein, Sarah; Fischhoff, Baruch; Layman, Mark; Combs, Barbara
A series of experiments studied how people judge the frequency of death from various causes. The judgments exhibited a highly consistent but systematically biased subjective scale of frequency. Two kinds of bias were identified: (a) a tendency to overestimate small frequencies and underestimate larger ones, and (b) a tendency to exaggerate the frequency of some specific causes and to underestimate the frequency of others, at any given level of objective frequency. These biases were traced to a number of possible sources, including disproportionate exposure, memorability, or imaginability of various events. Subjects were unable to correct for these sources of bias when specifically instructed to avoid them. Comparisons with precious laboratory studies are discussed, along with methods for improving frequency judgments and the implications of the present findings for the management of societal hazards.
Open Access
Judging Unlikely Conjunctions
(Decision Research, 1985-05) Fischhoff, Baruch
Several procedures were used to elicit direct numerical estimates of the probabilities associated with various events created by the conjunction of three independent subevents. However the question was asked, many respondents showed a misunderstanding of the conjunction rule. Less than one half met the minimal criterion of consistently assigning a probability to the conjunction that was no larger than that associated with the least likely constituent event. As a result, subjects as a whole greatly overestimated the conjunctive probability. When attention was restricted to individuals who had followed the conjunction rule, a tendency remained to overestimate the smallest probabilities, relative to the calculated values. Subsidiary results concerned the effects on judgment of wishful thinking, the similarity of the constituent events, and the source of the constituent events. The implications of these results for eliciting and presenting the probabilities of unlikely events are also discussed.
Open Access
Modeling the societal impact of fatal accidents
(1984) Slovic, Paul; Lichtenstein, Sarah; Fischhoff, Baruch
Open Access
Perceived risk: Psychological factors and social implications
(The Royal Society, 1981) Slovic, Paul; Fischhoff, Baruch; Lichtenstein, Sarah
Subjective judgments, whether by experts or lay people, are a major component in any risk assessment. If such judgments are faulty, risk management efforts are likely to be misdirected. This paper begins with an analysis of biases exhibited by lay people and experts when they make judgments about risk. Next the similarities and differences between lay and expert evaluations are examined in the context of a specific set of hazardous activities and technologies. Finally, insights from this research are applied to the problems of informing people about risk and forecasting public response towards nuclear power.
Open Access
Perception and Acceptability of Risk from Energy Systems
(Erlbaum, 1981) Fischhoff, Baruch; Lichtenstein, Sarah; Slovic, Paul
Open Access
Powerline frequency electric and magnetic fields: A pilot study of risk perception
(1985) Slovic, Paul; Nair, Indira; Giesler, Dan; Morgan, M. Granger; MacGregor, Donald G.; Fischhoff, Baruch; Lincoln, David; Florig, Keith
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 blankets on a variety of scales that have been found useful in characterizing people's risk attitudes and perceptions. These judgments allowed us to conjecture about the likely desire for regulation of these potential hazards and the likely response to a publicized problem (e.g., an accident or ominous research finding) involving these two sources of exposure. Various forms of detailed information about 50/60 Hz fields were supplied to respondents. The provision of information produced modest, but statistically significant, changes in perceptions in the direction of greater concern about the risks. In response to questions of public policy, participants desired modest regulatory control of field exposure from transmission lines and little or no control of field exposure from appliances like electric blankets.
Open Access
Prejudices about Bias
(Decision Research, 1985-05) Fischhoff, Baruch
Much recent research in the area of judgment and decision making has been dominated by documentation of ways in which people's intuitive thought processes can lead them astray. Like other psychological results that have cast doubt on people's abilities, these accounts have generated considerable controversy. From the set of criticisms that have been raised, a set of generic criticisms that could be raised is developed here. These include aspersions of methodological malpractice, advancement of alternative standards of optimality, and development of error theories showing the insensitivity of events to these kinds of problems. Considering these critici.sms in general form offers some perspectives on the continuing debate, some guidance on how to improve its productivity, and some hypotheses for analyzing analogous controversies elsewhere in psychology.