TALKING ABOUT PROBABILITIES: A LOGICAL PROBLEM FOR OR/MS

The correct interpretation of a natural language statement is determined as much by convention and shared meanings as by logical content. Therefore, when the word “probability” is used in the statement of a decision problem, the intended interpretation is not always clear. If such a statement also contains explicit probability formulae, confusion and even paradox may result. In this article, a problem involving cascaded inference is interpreted in four ways, three of which are regarded by the authors as legitimate or reasonable. The problem was originally suggested by Einhorn [3] and further discussed by Libby [10]. It is suggested here that a formal, mathematicist interpretation of the word “probability” might lead to inappropriate analyses of some decisions.     

The semantic distinction between "risk" and "danger": a linguistic analysis

The analysis combines frame semantic and corpus linguistic approaches in analyzing the role of agency and decision making in the semantics of the words "risk" and "danger" (both nominal and verbal uses). In frame semantics, the meanings of "risk" and of related words, such as "danger," are analyzed against the background of a specific cognitive-semantic structure (a frame) comprising frame elements such as Protagonist, Bad Outcome, Decision, Possession, and Source. Empirical data derive from the British National Corpus (100 million words). Results indicate both similarities and differences in use. First, both "risk" and "danger" are commonly used to represent situations having potential negative consequences as the result of agency. Second, "risk" and "danger," especially their verbal uses (to risk, to endanger), differ in agent-victim structure, i.e., "risk" is used to express that a person affected by an action is also the agent of the action, while "endanger" is used to express that the one affected is not the agent. Third, "risk," but not "danger," tends to be used to represent rational and goal-directed action. The results therefore to some extent confirm the analysis of "risk" and "danger" suggested by German sociologist Niklas Luhmann. As a point of discussion, the present findings arguably have implications for risk communication.     

Arguments for Testing Ethnic Identity and Acculturation as Factors in Risk Judgments

Understanding of risk views in multiethnic societies and in a globalizing world may be enhanced by use of measures of ethnic identity and acculturation. Ethnic identity includes such attributes as positive attitudes about one's ethnic group and a sense of belonging to it, voluntary and frequent association with other ethnic group members, and ethnic practices (preferred music, food, language; attendance at ethnic festivities). Acculturation is absorption of the "host" society's cultural norms, beliefs, attitudes and behavior patterns by immigrants, or by other groups historically excluded from the larger society. Both generic and ethnicity-specific measures of these concepts are available in the literature. This Perspective reviews the literature on risk implications of these concepts, how the nature of these measures presents both opportunities and challenges to risk researchers, and the degree to which ethnic identity and acculturation may be correlated with sociodemographic factors. Conceptual and methodological suggestions are made for risk research using these concepts, and hypotheses are offered about what such research might find.     

The Concepts of Risk,Safety, and Security: Applications in Everyday Language

The concepts of risk, safety, and security have received substantial academic interest. Several assumptions exist about their nature and relation. Besides academic use, the words risk, safety, and security are frequent in ordinary language, for example, in media reporting. In this article, we analyze the concepts of risk, safety, and security, and their relation, based on empirical observation of their actual everyday use. The “behavioral profiles” of the nouns risk, safety, and security and the adjectives risky, safe, and secure are coded and compared regarding lexical and grammatical contexts. The main findings are: (1) the three nouns risk, safety, and security, and the two adjectives safe and secure, have widespread use in different senses, which will make any attempt to define them in a single unified manner extremely difficult; (2) the relationship between the central risk terms is complex and only partially confirms the distinctions commonly made between the terms in specialized terminology; (3) whereas most attempts to define risk in specialized terminology have taken the term to have a quantitative meaning, nonquantitative meanings dominate in everyday language, and numerical meanings are rare; and (4) the three adjectives safe, secure, and risky are frequently used in comparative form. This speaks against interpretations that would take them as absolute, all‐or‐nothing concepts.     

Direct Inference, Probability, and a Conceptual Gulf in Risk Communication

Differences in the conceptual frameworks of scientists and nonscientists may create barriers to risk communication. This article examines two such conceptual problems. First, the logic of "direct inference" from group statistics to probabilities about specific individuals suggests that individuals might be acting rationally in refusing to apply to themselves the conclusions of regulatory risk assessments. Second, while regulators and risk assessment scientists often use an "objectivist" or "relative frequency" interpretation of probability statements, members of the public are more likely to adopt a "subjectivist" or "degree of confidence" interpretation when estimating their personal risks, and either misunderstand or significantly discount the relevance of risk assessment conclusions. If these analyses of inference and probability are correct, there may be a conceptual gulf at the center of risk communication that cannot be bridged by additional data about the magnitude of group risk. Suggestions are made for empirical studies that might help regulators deal with this conceptual gulf.     

Trust in Risky Messages: The Role of Prior Attitudes

Risk perception researchers have observed a "negativity bias" for hazard-related information. Messages indicating the presence of risk seem to be trusted more than messages indicating the absence of risk, and risk perceptions seem more affected by negative than positive information. Two experiments were conducted to examine alternative explanations of this finding within the area of food additives. Study 1 (N = 235) extended earlier work by (a) unconfounding message valence (positive or negative) from message extremity (definite or null finding) and (b) exploring the role of prior attitudes. Results suggested that negative/risky messages were indeed trusted more even when extremity was taken into account. However, prior attitudes significantly moderated the effect of message valence on trust. Positive messages were distrusted only by those with negative prior attitudes. Study 2 (N = 252), further explored the role of prior attitudes and extended the work by examining reactions to risky messages about a positively viewed additive--a vitamin. The results again found a moderating effect of prior attitudes on message valence. Participants had greater confidence in messages that were more congruent with their prior attitudes, irrespective of valence. Furthermore, positive messages had a greater impact on risk perception than negative messages. These findings suggest that greater trust in negative messages about hazards may be a product of a "confirmatory" rather than a "negativity" bias.     

What Risks Do People Perceive in Everyday Life? A Perspective Gained from the Experience Sampling Method (ESM)

The experience sampling method (ESM) was used to collect data from 74 part-time students who described and assessed the risks involved in their current activities when interrupted at random moments by text messages. The major categories of perceived risk were short term in nature and involved "loss of time or materials" related to work and "physical damage" (e.g., from transportation). Using techniques of multilevel analysis, we demonstrate effects of gender, emotional state, and types of risk on assessments of risk. Specifically, females do not differ from males in assessing the potential severity of risks but they see these as more likely to occur. Also, participants assessed risks to be lower when in more positive self-reported emotional states. We further demonstrate the potential of ESM by showing that risk assessments associated with current actions exceed those made retrospectively. We conclude by noting advantages and disadvantages of ESM for collecting data about risk perceptions.     

What's Wrong with Risk Matrices?

Risk matrices—tables mapping "frequency" and "severity" ratings to corresponding risk priority levels—are popular in applications as diverse as terrorism risk analysis, highway construction project management, office building risk analysis, climate change risk management, and enterprise risk management (ERM). National and international standards (e.g., Military Standard 882C and AS/NZS 4360:1999) have stimulated adoption of risk matrices by many organizations and risk consultants. However, little research rigorously validates their performance in actually improving risk management decisions. This article examines some mathematical properties of risk matrices and shows that they have the following limitations. (a) Poor Resolution . Typical risk matrices can correctly and unambiguously compare only a small fraction (e.g., less than 10%) of randomly selected pairs of hazards. They can assign identical ratings to quantitatively very different risks ("range compression"). (b) Errors . Risk matrices can mistakenly assign higher qualitative ratings to quantitatively smaller risks. For risks with negatively correlated frequencies and severities, they can be "worse than useless," leading to worse-than-random decisions. (c) Suboptimal Resource Allocation . Effective allocation of resources to risk-reducing countermeasures cannot be based on the categories provided by risk matrices. (d) Ambiguous Inputs and Outputs . Categorizations of severity cannot be made objectively for uncertain consequences. Inputs to risk matrices (e.g., frequency and severity categorizations) and resulting outputs (i.e., risk ratings) require subjective interpretation, and different users may obtain opposite ratings of the same quantitative risks. These limitations suggest that risk matrices should be used with caution, and only with careful explanations of embedded judgments.     

Reflections on Risk Perception and Policy1,2

This paper looks critically at the emergence and present status of risk analysis with the aim of assessing its usefulness for policy decisions on risk regulation and the acceptability of risk-bearing innovations. The authors adopt a personal narrative to illustrate their own involvement in risk research and to comment on empirical trends that have resulted in the current fashion for risk workshops. The second part of the paper confronts specific issues in risk research. These are not new problems-indeed several of the questions asked have been taken directly from a list used to structure a recent risk seminar; but the stand taken here is rather less conciliatory than is usual when these issues are discussed. The pessimistic message of this paper is that risk research, especially in the area of risk perception, is being used as a panacea with which to attempt to remedy what are essentially societal and political matters. Risk research is being used as a tool in a discourse which is not concerned with risks per se, nor with the cognitive processes by which people misperceive the risks of new technologies, but whose hidden agenda is the legitimacy of decision-making institutions and the equitable distribution of hazards and benefits. The authors take a subjectivist view, not just of risk but in general, and query the natural science approach to risk perception, with its assumption that universal dimensions of risk perception can be discovered and used in policy-making and setting regulatory standards. Although it is possible to collect subjective data on the wider meanings that risks and benefits associated with technological innovations have for lay publics, the interpretation and recombination of these data into useful policy guidelines is seen as fraught with technical and, above all, political problems.     

On The Quantitative Definition of Risk

A quantitative definition of risk is suggested in terms of the idea of a "set of triplets". The definition is extended to include uncertainty and completeness, and the use of Bayes' theorem is described in this connection. The definition is used to discuss the notions of "relative risk", "relativity of risk", and "acceptability of risk".     

The Role of the Affect and Availability Heuristics in Risk Communication

Results of past research suggest that affect plays an important role in risk perception. Because affect may also increase the availability of risks, affect and availability are closely related concepts. Three studies tested the hypothesis that evoking negative affect (fear), either through past experience or through experimental manipulation, results in greater perceived risk. The present research focused on perception of flooding risk. Study 1 and Study 2 showed that participants who received risk information concerning a longer time period (e.g., 30 years) perceived more danger compared with participants who received risk information for one year. Study 2 showed that the interpretation of risk information was influenced by participants' own experiences with flooding. In Study 3, affect was experimentally manipulated. After looking at photographs depicting houses in a flooded region, participants perceived greater risk compared with participants in a control group. Taken together, the results of these three studies suggest that affect is important for successful risk communication. Results of the present research are in line with the affect heuristic proposed by Slovic and colleagues.     

Representations as Decision Aids: The Asymmetric Effects of Words and Numbers on Auditors' Inherent Risk Judgments*

Decision aids often change the representations used to express risk cue information and communicate risk judgments. In this study, we hypothesize that numbers and words may have asymmetric effects when used to represent risk cue information as opposed to when used to communicate risk judgments. Specifically, decision makers' agreement on cue weights and judgment consensus may be higher with cue information stated in words rather than numbers, since appropriately chosen words can more directly convey the risk implications of information cues. In contrast, decision makers' consistency in applying their judgment policies and judgment consensus may be higher with risk judgments communicated in numbers instead of words, because the greater precision available with numbers allows finer discriminations of risk. To test our hypotheses, we conducted an experiment in which experienced financial auditors made inherent risk judgments for a hypothetical manufacturing client. Cue and response representations were manipulated between numbers and words. The results generally support our arguments. In addition, representing cue information in words increased the time required to acquire cue information relative to numeric representation. In contrast, requiring auditors to express their risk judgments in numbers increased the time required to express risk assessments relative to     

Enhancing Self‐Protective Behavior: Efficacy Beliefs and Peer Feedback in Risk Communication

In times of a high‐impact safety incident citizens may have a variety of sources available to help them cope with the situation. This research focuses on the interplay of efficacy information in risk communication messages and peer feedback, such as responses on social network sites (SNSs) in the context of a high‐impact risk on the intention to engage in self‐protective behavior. The study pitted high and low efficacy information messages against supporting and opposing peer feedback (N = 242). Results show a significant interaction effect between efficacy information in a news article and peer feedback from SNS messages on both the intention to engage in self‐protective behavior and levels of involvement. Participants who received the article with more efficacy information and also received supportive peer feedback via SNS messages were more likely to express higher levels of involvement and greater intentions to engage in protective behavior. When confronted with a low efficacious news article, the effect of peer feedback on these two variables was significantly stronger. Finally, implications for theory and government risk communication are discussed.     

An Overview of a Multimedia Benchmarking Analysis for Three Risk Assessment Models: RESRAD, MMSOILS, and MEPAS

Multimedia modelers from the United States Environmental Protection Agency (EPA) and the United States Department of Energy (DOE) collaborated to conduct a detailed and quantitative benchmarking analysis of three multimedia models. The three models—RESRAD (DOE), MMSOILS (EPA), and MEPAS (DOE)—represent analytically-based tools that are used by the respective agencies for performing human exposure and health risk assessments. The study is performed by individuals who participate directly in the ongoing design, development, and application of the models. Model form and function are compared by applying the models to a series of hypothetical problems, first isolating individual modules (e.g., atmospheric, surface water, groundwater) and then simulating multimedia-based risk resulting from contaminant release from a single source to multiple environmental media. Study results show that the models differ with respect to environmental processes included (i.e., model features) and the mathematical formulation and assumptions related to the implementation of solutions. Depending on the application, numerical estimates resulting from the models may vary over several orders-of-magnitude. On the other hand, two or more differences may offset each other such that model predictions are virtually equal. The conclusion from these results is that multimedia models are complex due to the integration of the many components of a risk assessment and this complexity must be fully appreciated during each step of the modeling process (i.e., model selection, problem conceptualization, model application, and interpretation of results).     

Unquestioned Answers or Unanswered Questions: Beliefs About Science Guide Responses to Uncertainty in Climate Change Risk Communication

In two experimental studies we investigated the effect of beliefs about the nature and purpose of science (classical vs. Kuhnian models of science) on responses to uncertainty in scientific messages about climate change risk. The results revealed a significant interaction between both measured (Study 1) and manipulated (Study 2) beliefs about science and the level of communicated uncertainty on willingness to act in line with the message. Specifically, messages that communicated high uncertainty were more persuasive for participants who shared an understanding of science as debate than for those who believed that science is a search for absolute truth. In addition, participants who had a concept of science as debate were more motivated by higher (rather than lower) uncertainty in climate change messages. The results suggest that achieving alignment between the general public's beliefs about science and the style of the scientific messages is crucial for successful risk communication in science. Accordingly, rather than uncertainty always undermining the effectiveness of science communication, uncertainty can enhance message effects when it fits the audience's understanding of what science is.     

A LOOK AT THE SEMANTIC DIFFERENTIAL AS A TOOL TO ASSIST FACULTY TEACHING EVALUATIONS

The evaluation of the effectiveness of faculty teaching is a difficult process. This paper presents the results of an experimental empirical investigation into the possibility of using a psycho-linguistic measurement technique, the Semantic Differential, to measure faculty communication of terminology to students. This measurement could be used to supplement other teaching evaluation devices. The paper determines a set of “key concepts,” derives a set of S.D. meanings from a Faculty to act as a standard, and measures student meanings at the beginning and end of an introductory course. These sets of meanings are then compared.     

Probability Information in Risk Communication: A Review of the Research Literature

Communicating probability information about risks to the public is more difficult than might be expected. Many studies have examined this subject, so that their resulting recommendations are scattered over various publications, diverse research fields, and are about different presentation formats. An integration of empirical findings in one review would be useful therefore to describe the evidence base for communication about probability information and to present the recommendations that can be made so far. We categorized the studies in the following presentation formats: frequencies, percentages, base rates and proportions, absolute and relative risk reduction, cumulative probabilities, verbal probability information, numerical versus verbal probability information, graphs, and risk ladders. We suggest several recommendations for these formats. Based on the results of our review, we show that the effects of presentation format depend not only on the type of format, but also on the context in which the format is used. We therefore argue that the presentation format has the strongest effect when the receiver processes probability information heuristically instead of systematically. We conclude that future research and risk communication practitioners should not only concentrate on the presentation format of the probability information but also on the situation in which this message is presented, as this may predict how people process the information and how this may influence their interpretation of the risk.     

Framing Effects in Narrative and Non‐Narrative Risk Messages

Narrative messages are increasingly popular in health and risk campaigns, yet gain/loss framing effects have never been tested with such messages. Three experiments examined framing in narrative messages. Experiment 1 found that only the character's decision, not framing, influenced judgments about characters in a narrative derived from a prospect theory context. Experiment 2 found that a framing effect that occurred when presented in a decision format did not occur when the same situation was presented as a narrative. Using a different story/decision context, Experiment 3 found no significant difference in preference for surgery over radiation therapy in a narrative presentation compared to a non‐narrative presentation. The results suggest that health and risk campaigns cannot assume that framing effects will be the same in narrative messages and non‐narrative messages. Potential reasons for these differences and suggestions for future research are discussed.     

Risk Perception Among Smokers: A Qualitative Study

The aim of this qualitative study is to identify the dimensions people used to assess the risk of smoking and then compare them with those used by health professionals in primary healthcare. Five discussion groups were conducted. The field work was carried out in Barcelona (Spain), from February 2005 to January 2006. Data were analyzed following a semantic‐thematic categorical content analysis (ACC‐ts). Results showed that people tend to employ stereotypical discourses when evaluating the risk of smoking. Similarly, they reassess the risk in the context of their life experience and incorporate new nuances to the arguments sustaining their behavior. Once this reassessment takes place, the decision to continue smoking emerges, and smokers come up with additional arguments justifying their habit (i.e., age, benefits related to costs). Professionals are aware of this process and its multidimensional nature. Nevertheless, their discourse loses this multidimensional feature when discussing the strategies they use at smoking cessation interventions. This qualitative study increases the understanding of various meanings that people attribute to their life experience. These assumptions may be useful for developing health practices that are closer to people. As a practical utility of these results, it would be interesting to apply a preliminary assessment of the different meanings that people attribute to smoking from their life context in risk communication.     

Loss/Gain Framing,Dose, and Reactance: A Message Experiment

Whether a loss or gain frame has a persuasive advantage in communicating health risks is a matter of ongoing debate. Findings reported in the literature are mixed, suggesting that framing effects are likely complex and may be influenced by a combination of factors. This study examined reactance as a mediator and dose as a moderator of loss/gain framing effects. Adults (N = 1,039) read framed messages about the health consequences of physical (in)activity in varying message doses (i.e., number of framed statements). Compared to loss frames, gain frames generated more threat to freedom and reactance. Dosage exerted significant influence at the extremes; the one‐dose messages invoked less intentions to exercise compared to the four‐dose messages. Planned contrasts revealed significant frame × dose interactions. Notably, the one‐dose gain‐framed messages triggered significantly more freedom threat and less intentions to engage in physical activity—a situation that changed when the information was loss‐framed or when the dosage was increased.