Visualizing seismic risk and uncertainty: a review of related research

Trend effects on perceived avalanche hazard

Hazard-level forecasts constitute an important risk mitigation tool to reduce loss of economic values and human life. Avalanche forecasts represent an example of this. As for many other domains, avalanche risk is communicated using a color-coded, categorical risk scale aimed at informing the public about past, current, and future risk. We report the results from three experiments in which we tested if an irrelevant past trend in forecasted avalanche danger affects perceptions of current and future avalanche risk. Our sample consisted of individuals from three different populations targeted by national avalanche warning services. All three experiments showed that the perception of avalanche risk is influenced by the trend, but that the effect is opposite for perceptions of current and expectations of future avalanche risk. While future avalanche risk is extrapolated in the same direction as the change from the previous day, we found that perceived current risk appears to be based on an average of past and current risk. These effects diminish when we provide participants with a scale indicating the exact level of avalanche danger. For most of our measurement instruments, however, the effects remain significant. These results imply that targeted populations may consider historic information more than was intended by the sender. As such, our results have implications for both avalanche warning services and risk communication in general.

Evaluating the effectiveness and efficiency of risk communication for maps depicting the hazard of COVID-19

COVID-19 maps convey hazard and risk information to the public, which play an important role in the risk communication for individual protection. The aim of this study is to improve the effectiveness and efficiency of communicating the specific risk of COVID-19 maps. By testing 71 subjects from Wuhan, China, this study explored how color schemes (cool, warm, and mixed colors) and data presentation forms (choropleth maps, graduated symbol maps) influence visual cognition patterns, risk perception, comprehension, and subjective satisfaction. The results indicated that the warm scheme (yellow/red) has significant strengths in visual cognition and understanding, and the choropleth map (vs. the graduated symbol map) has significant strengths in risk expression. On subjective satisfaction, the combination of the mixed scheme (blue/yellow/red) and the choropleth map scored highest mean value. These results have implications for enhancing the focused functions of COVID-19 maps that fit different terms: in the early and medium terms of disease transmission, choropleth maps with warm or cool colors should be considered as a priority design for their better risk perception. When the epidemic conditions are on the upturn, a better reading experience combination of choropleth maps with mixed colors can be considered.

A comparative analysis on risk communication between international and Chinese literature from the perspective of knowledge domain visualization

BACKGROUND

The outbreak of coronavirus disease (COVID-19) severely damaged and endangered people's lives at the end of 2019. Risk communication plays an important role in the response to it successfully, which has been appreciated by the World Health Organization. Therefore, a comprehensive analysis of risk communication research is necessary, which can understand current research hotspots and reveal new trends.

METHODS

In this study, we collected 1134 international articles from the Web of Science database and 3983 Chinese articles from the China National Knowledge Infrastructure database. Bibliometric and mapping knowledge domain analysis methods were used for temporal distribution analysis, cooperation network analysis, co-word network analysis, and burst detection analysis.

RESULTS

The first article in this field was published by western scholars earlier, while the first Chinese article in 2002. Research institutions mainly come from universities. The USA plays a key role in this field. Chinese scholars had a closer cooperation network, but there was less cooperation among domestic institutions. Risk perception, trust, risk management, and risk information had always been the research hotspots in this academic. Trust, sentiment research, and public risk events were essential directions for the future. There are 25 burst words for international articles, while 11 burst words for Chinese articles from 2000 to 2020.

CONCLUSIONS

In summary, both domestic and international researchers are concerned about risk communication, risk perception, trust, and risk information. International research on risk communication is systematic and comprehensive relatively. However, Chinese scholars take severe acute respiratory syndrome as the research background and reviewing foreign knowledge as the research starting point. With the purpose of practical and applied research based on a public emergency, the risk communication research lacks continuity in Chinese academy in the past years.

Achieving Accuracy through Ambiguity: the Interactivity of Risk Communication in Severe Weather Events

Risks associated with natural hazards such as hurricanes are increasingly communicated on social media. For hurricane risk communication, visual information products—graphics—generated by meteorologists and scientists at weather agencies portray forecasts and atmospheric conditions and are offered to parsimoniously convey predictions of severe storms. This research considers risk interactivity by examining a particular hurricane graphic which has shown in previous research to have a distinctive diffusion signature: the ‘spaghetti plot’, which contains multiple discrete lines depicting a storm’s possible path. We first analyzed a large dataset of microblog interactions around spaghetti plots between members of the public and authoritative weather sources within the US during the 2017 Atlantic hurricane season. We then conducted interviews with a sample of the weather authorities after preliminary findings sketched the role that experts have in such communications. Findings describe how people make sense of risk dialogically over graphics, and show the presence of a fundamental tension in risk communication between accuracy and ambiguity. The interactive effort combats the unintended declarative quality of the graphical risk representation through communicative acts that maintain a hazard’s inherent ambiguity until risk can be foreclosed. We consider theoretical and practice-based implications of the limits and potentials of graphical risk representations and of widely diffused scientific communication, and offer reasons we need CSCW attention paid to the larger enterprise of risk communication.

Visualizations Out of Context: Addressing Pitfalls of Real-Time Realistic Hazard Visualizations

Realistic 3D hazard visualizations based on advanced Geographic Information Systems (GIS) may be directly driven by hydrodynamic and wind model outputs (e.g., ADCIRC, the ADvanced CIRCulation Model) and hazard impact modeling (e.g., predicting damage to structures and infrastructure). These methods create new possibilities for representing hazard impacts and support the development of near-real-time hazard forecasting and communication tools. This paper considers the wider implications of using these storm visualizations in light of current frameworks in the context of landscape and urban planning and cartography that have addressed the use of realistic 3D visualizations. Visualizations used outside of engagement processes organized by experts risk misleading the public and may have consequences in terms of feelings of individual self-efficacy or perception of scientists behind the visualizations. In addition to summarizing the implications of using these visualizations outside of recommended practices, a research agenda is proposed to guide the development of real-time realistic and semi-realistic visualizations for future use in hazard communication. Development of a clearer use-case for real-time visualization capabilities is an essential first step if such work is to continue.

Robustness of individual and marginal model-based estimates: A sensitivity analysis of flexible parametric models

BACKGROUND

Flexible parametric survival models (FPMs) are commonly used in epidemiology. These are preferred as a wide range of hazard shapes can be captured using splines to model the log-cumulative hazard function and can include time-dependent effects for more flexibility. An important issue is the number of knots used for splines. The reliability of estimates are assessed using English data for 10 cancer types and the use of online interactive graphs to enable a more comprehensive sensitivity analysis at the control of the user is demonstrated.

METHODS

Sixty FPMs were fitted to each cancer type with varying degrees of freedom to model the baseline excess hazard and the main and time-dependent effect of age. For each model, we obtained age-specific, age-group and internally age-standardised relative survival estimates. The Akaike Information Criterion and Bayesian Information Criterion were also calculated and comparative estimates were obtained using the Ederer II and Pohar Perme methods. Web-based interactive graphs were developed to present results.

RESULTS

Age-standardised estimates were very insensitive to the exact number of knots for the splines. Age-group survival is also stable with negligible differences between models. Age-specific estimates are less stable especially for the youngest and oldest patients, of whom there are very few, but for most scenarios perform well.

CONCLUSION

Although estimates do not depend heavily on the number of knots, too few knots should be avoided, as they can result in a poor fit. Interactive graphs engage researchers in assessing model sensitivity to a wide range of scenarios and their use is highly encouraged.

Residential Location and Psychological Distance in Americans' Risk Views and Behavioral Intentions Regarding Zika Virus

Two 2017 experiments with a U.S. national opportunity sample tested effects of location, psychological distance (PD), and exposure to location-related information on Americans' Zika risk views and behavioral intentions. Location-distance from mosquito transmission of the virus in Florida and Texas; residence within states with 100+ Zika infections; residence within potential mosquito vector ranges-had small, inconsistent effects. Hazard proximity weakly enhanced personal risk judgments and concern about Zika transmission locally. It also increased psychological proximity, and intentions of mosquito control, avoiding travel to Zika-infected areas, and practicing safe sex. PD-particularly social and geographical distance, followed by temporal distance, with few effects for uncertainty-modestly and inconsistently decreased risk views and intentions. Exposure to location-related information from the U.S. Centers for Disease Control and Prevention website-naming states with 100+ Zika cases; maps of potential mosquito vector habitat-increased risk views and psychological closeness, but not intentions; maps had slightly stronger if inconsistent effects versus prevalence information. Structural equation modeling (SEM) of a location > PD > risk views > intention path explained modest variance in intentions. This varied in degree and kind (e.g., which location measures were significant) across behaviors, and between pre- and postinformation exposure analyses. These results suggest need for both theoretical and measurement advances regarding effects of location and PD on risk views and behavior. PD mediates location effects on risk views. Online background information, like that used here, will not enhance protective behavior without explicitly focused communication and perhaps higher objective risk.

Retweeting Risk Communication: The Role of Threat and Efficacy

Social media platforms like Twitter and Facebook provide risk communicators with the opportunity to quickly reach their constituents at the time of an emerging infectious disease. On these platforms, messages gain exposure through message passing (called "sharing" on Facebook and "retweeting" on Twitter). This raises the question of how to optimize risk messages for diffusion across networks and, as a result, increase message exposure. In this study we add to this growing body of research by identifying message-level strategies to increase message passing during high-ambiguity events. In addition, we draw on the extended parallel process model to examine how threat and efficacy information influence the passing of Zika risk messages. In August 2016, we collected 1,409 Twitter messages about Zika sent by U.S. public health agencies' accounts. Using content analysis methods, we identified intrinsic message features and then analyzed the influence of those features, the account sending the message, the network surrounding the account, and the saliency of Zika as a topic, using negative binomial regression. The results suggest that severity and efficacy information increase how frequently messages get passed on to others. Drawing on the results of this study, previous research on message passing, and diffusion theories, we identify a framework for risk communication on social media. This framework includes four key variables that influence message passing and identifies a core set of message strategies, including message timing, to increase exposure to risk messages on social media during high-ambiguity events.

Real-Time Chronological Hazard Impact Modeling

The potential of using ADvanced CIRCulation model (ADCIRC) to assess the time incremented progression of hazard impacts on individual critical facilities has long been recognized but is not well described. As ADCIRC is applied to create granular impact models, the lack of transparency in the methods is problematic. It becomes difficult to evaluate the entire system in situations where modeling integrates different types of data (e.g., hydrodynamic and existing geospatial point data) and involves multiple disciplines and stakeholders. When considering increased interest in combining hydrodynamic models, existing geospatial information, and advanced visualizations it is necessary to increase transparency and identify the pitfalls that arise out of this integration (e.g., the inadequacy of data to support the resolution of proposed outputs). This paper thus describes an all numerical method to accomplish this integration. It provides an overview of the generation of the hydrodynamic model, describes the all numerical method utilized to model hazard impacts, identifies pitfalls that arise from the integration of existing geospatial data with the hydrodynamic model, and describes an approach to developing a credible basis for determining impacts at a granular scale. The paper concludes by reflecting on the implementation of these methods as part of a Federal Emergency Management Agency (FEMA) Integrated Emergency Management Training Course (IEMC) and identifies the need to further study the effects of integrated models and visualizations on risk perception.

InterPreT cancer survival: A dynamic web interactive prediction cancer survival tool for health-care professionals and cancer epidemiologists

BACKGROUND

There are a variety of ways for quantifying cancer survival with each measure having advantages and disadvantages. Distinguishing these measures and how they should be interpreted has led to confusion among scientists, the media, health care professionals and patients. This motivates the development of tools to facilitate communication and interpretation of these statistics.

METHODS

"InterPreT Cancer Survival" is a newly developed, publicly available, online interactive cancer survival tool targeted towards health-care professionals and epidemiologists (http://interpret.le.ac.uk). It focuses on the correct interpretation of commonly reported cancer survival measures facilitated through the use of dynamic interactive graphics. Statistics presented are based on parameter estimates obtained from flexible parametric relative survival models using large population-based English registry data containing information on survival across 6 cancer sites; Breast, Colon, Rectum, Stomach, Melanoma and Lung.

RESULTS

Through interactivity, the tool improves understanding of various measures and how survival or mortality may vary by age and sex. Routine measures of cancer survival are reported, however, individualised estimates using crude probabilities are advocated, which is more appropriate for patients or health care professionals. The results are presented in various interactive formats facilitating understanding of individual risk and differences between various measures.

CONCLUSIONS

"InterPreT Cancer Survival" is presented as an educational tool which engages the user through interactive features to improve the understanding of commonly reported cancer survival statistics. The tool has received positive feedback from a Cancer Research UK patient sounding board and there are further plans to incorporate more disease characteristics, e.g. stage.

Communicating Low-Probability High-Consequence Risk, Uncertainty and Expert Confidence: Induced Seismicity of Deep Geothermal Energy and Shale Gas

Subsurface energy activities entail the risk of induced seismicity including low-probability high-consequence (LPHC) events. For designing respective risk communication, the scientific literature lacks empirical evidence of how the public reacts to different written risk communication formats about such LPHC events and to related uncertainty or expert confidence. This study presents findings from an online experiment (N = 590) that empirically tested the public's responses to risk communication about induced seismicity and to different technology frames, namely deep geothermal energy (DGE) and shale gas (between-subject design). Three incrementally different formats of written risk communication were tested: (i) qualitative, (ii) qualitative and quantitative, and (iii) qualitative and quantitative with risk comparison. Respondents found the latter two the easiest to understand, the most exact, and liked them the most. Adding uncertainty and expert confidence statements made the risk communication less clear, less easy to understand and increased concern. Above all, the technology for which risks are communicated and its acceptance mattered strongly: respondents in the shale gas condition found the identical risk communication less trustworthy and more concerning than in the DGE conditions. They also liked the risk communication overall less. For practitioners in DGE or shale gas projects, the study shows that the public would appreciate efforts in describing LPHC risks with numbers and optionally risk comparisons. However, there seems to be a trade-off between aiming for transparency by disclosing uncertainty and limited expert confidence, and thereby decreasing clarity and increasing concern in the view of the public.

Developing citizen report cards for primary health care in low and middle-income countries: Results from cognitive interviews in rural Tajikistan

Citizen report cards on health care providers have been identified as a potential means to increase citizen engagement, provider accountability and health systems performance. Research in high-income settings indicates that the wording, presentation and display of performance information are critical to achieve these goals. However, there are limited insights on developing effective report card designs for middle- and low-income settings. We conducted cognitive interviews to assess consumers’ understanding, interpretation of and preferences for displaying information for a health care report card in rural Tajikistan. We recruited a convenience sample of 40 citizens (20 women and 20 men aged 18–45) from rural areas of two provinces of Tajikistan (Soghd and Khatlon oblasts). The interview protocol was adapted from the model of cognitive interviews used in social science research to improve survey questionnaires. We used multivariate regression to assess understanding and interpretation of the report card; chi2 tests to assess differences in preferences for displaying information; and tests of proportions to assess the preferred comparison group. Respondents understood the main idea of the report card and are not confused by the indicators or display. However, many respondents had difficulties making comparisons, and when asked to identify worst-performing services. Respondents preferred detailed rankings using school grades, comparisons of their local clinic with the regional or national average performance, and the use of color in the report card. We found some heterogeneity across the two provinces. Overall, our findings are promising regarding the citizens’ comprehension of health care report cards in rural Tajikistan, while underscoring the challenges of effectively providing health care performance information to communities. Cognitive interviews and iterative testing can support an effective implementation of reporting initiatives.

Tailoring the visual communication of climate projections for local adaptation practitioners in Germany and the UK

Visualizations are widely used in the communication of climate projections. However, their effectiveness has rarely been assessed among their target audience. Given recent calls to increase the usability of climate information through the tailoring of climate projections, it is imperative to assess the effectiveness of different visualizations. This paper explores the complexities of tailoring through an online survey conducted with 162 local adaptation practitioners in Germany and the UK. The survey examined respondents' assessed and perceived comprehension (PC) of visual representations of climate projections as well as preferences for using different visualizations in communicating and planning for a changing climate. Comprehension and use are tested using four different graph formats, which are split into two pairs. Within each pair the information content is the same but is visualized differently. We show that even within a fairly homogeneous user group, such as local adaptation practitioners, there are clear differences in respondents' comprehension of and preference for visualizations. We do not find a consistent association between assessed comprehension and PC or use within the two pairs of visualizations that we analysed. There is, however, a clear link between PC and use of graph format. This suggests that respondents use what they think they understand the best, rather than what they actually understand the best. These findings highlight that audience-specific targeted communication may be more complex and challenging than previously recognized.

Literature review of visual representation of the results of benefit-risk assessments of medicinal products

BACKGROUND

The PROTECT Benefit-Risk group is dedicated to research in methods for continuous benefit-risk monitoring of medicines, including the presentation of the results, with a particular emphasis on graphical methods.

METHODS

A comprehensive review was performed to identify visuals used for medical risk and benefit-risk communication. The identified visual displays were grouped into visual types, and each visual type was appraised based on five criteria: intended audience, intended message, knowledge required to understand the visual, unintentional messages that may be derived from the visual and missing information that may be needed to understand the visual.

RESULTS

Sixty-six examples of visual formats were identified from the literature and classified into 14 visual types. We found that there is not one single visual format that is consistently superior to others for the communication of benefit-risk information. In addition, we found that most of the drawbacks found in the visual formats could be considered general to visual communication, although some appear more relevant to specific formats and should be considered when creating visuals for different audiences depending on the exact message to be communicated.

CONCLUSION

We have arrived at recommendations for the use of visual displays for benefit-risk communication. The recommendation refers to the creation of visuals. We outline four criteria to determine audience-visual compatibility and consider these to be a key task in creating any visual. Next we propose specific visual formats of interest, to be explored further for their ability to address nine different types of benefit-risk analysis information.

Forecasting forecasts: The trend effect

People often make predictions about the future based on trends they have observed in the past. Revised probabilistic forecasts can be perceived by the public as indicative of such a trend. In five studies, we describe experts who make probabilistic forecasts of various natural events (effects of climate changes, landslide and earthquake risks) at two points in time. Prognoses that have been upgraded or downgraded from T1 to T2 were in all studies expected to be updated further, in the same direction, later on (at T3). Thus, two prognoses were in these studies enough to define a trend, forming the basis for future projections. This “trend effect” implies that non-experts interpret recent forecast in light of what the expert said in the past, and think, for instance, that a “moderate” landslide risk will cause more worry if it has previously been low than if it has been high. By transcending the experts’ most recent forecasts the receivers are far from conservative, and appear to know more about the experts’ next prognoses than the experts themselves.

Testing Map Features Designed to Convey the Uncertainty of Cancer Risk: Insights Gained From Assessing Judgments of Information Adequacy and Communication Goals

Barriers to communicating the uncertainty of environmental health risks include preferences for certain information and low numeracy. Map features designed to communicate the magnitude and uncertainty of estimated cancer risk from air pollution were tested among 826 participants to assess how map features influenced judgments of adequacy and the intended communication goals. An uncertain versus certain visual feature was judged as less adequate but met both communication goals and addressed numeracy barriers. Expressing relative risk using words communicated uncertainty and addressed numeracy barriers but was judged as highly inadequate. Risk communication and visual cognition concepts were applied to explain findings.

Visualizing the variability of gradients in uncertain 2D scalar fields

In uncertain scalar fields where data values vary with a certain probability, the strength of this variability indicates the confidence in the data. It does not, however, allow inferring on the effect of uncertainty on differential quantities such as the gradient, which depend on the variability of the rate of change of the data. Analyzing the variability of gradients is nonetheless more complicated, since, unlike scalars, gradients vary in both strength and direction. This requires initially the mathematical derivation of their respective value ranges, and then the development of effective analysis techniques for these ranges. This paper takes a first step into this direction: Based on the stochastic modeling of uncertainty via multivariate random variables, we start by deriving uncertainty parameters, such as the mean and the covariance matrix, for gradients in uncertain discrete scalar fields. We do not make any assumption about the distribution of the random variables. Then, for the first time to our best knowledge, we develop a mathematical framework for computing confidence intervals for both the gradient orientation and the strength of the derivative in any prescribed direction, for instance, the mean gradient direction. While this framework generalizes to 3D uncertain scalar fields, we concentrate on the visualization of the resulting intervals in 2D fields. We propose a novel color diffusion scheme to visualize both the absolute variability of the derivative strength and its magnitude relative to the mean values. A special family of circular glyphs is introduced to convey the uncertainty in gradient orientation. For a number of synthetic and real-world data sets, we demonstrate the use of our approach for analyzing the stability of certain features in uncertain 2D scalar fields, with respect to both local derivatives and feature orientation.

The influence of uncertain map features on risk beliefs and perceived ambiguity for maps of modeled cancer risk from air pollution

Maps are often used to convey information generated by models, for example, modeled cancer risk from air pollution. The concrete nature of images, such as maps, may convey more certainty than warranted for modeled information. Three map features were selected to communicate the uncertainty of modeled cancer risk: (i) map contours appeared in or out of focus, (ii) one or three colors were used, and (iii) a verbal-relative or numeric risk expression was used in the legend. Study aims were to assess how these features influenced risk beliefs and the ambiguity of risk beliefs at four assigned map locations that varied by risk level. We applied an integrated conceptual framework to conduct this full factorial experiment with 32 maps that varied by the three dichotomous features and four risk levels; 826 university students participated. Data was analyzed using structural equation modeling. Unfocused contours and the verbal-relative risk expression generated more ambiguity than their counterparts. Focused contours generated stronger risk beliefs for higher risk levels and weaker beliefs for lower risk levels. Number of colors had minimal influence. The magnitude of risk level, conveyed using incrementally darker shading, had a substantial dose-response influence on the strength of risk beliefs. Personal characteristics of prior beliefs and numeracy also had substantial influences. Bottom-up and top-down information processing suggest why iconic visual features of incremental shading and contour focus had the strongest visual influences on risk beliefs and ambiguity. Variations in contour focus and risk expression show promise for fostering appropriate levels of ambiguity.

The influence of environmental hazard maps on risk beliefs, emotion, and health-related behavioral intentions

To test a theoretical explanation of how attributes of mapped environmental health hazards influence health-related behavioral intentions and how beliefs and emotion mediate the influences of attributes, 24 maps were developed that varied by four attributes of a residential drinking water hazard: level, proximity, prevalence, and density. In a factorial design, student participants (N = 446) answered questions about a subset of maps. Hazard level and proximity had the largest influences on intentions to test water and mitigate exposure. Belief in the problem's seriousness mediated attributes' influence on intention to test drinking water, and perceived susceptibility mediated the influence of attributes on intention to mitigate risk. Maps with carefully illustrated attributes of hazards may promote appropriate health-related risk beliefs, intentions, and behavior.

Visual Semiotics & Uncertainty Visualization: An Empirical Study

This paper presents two linked empirical studies focused on uncertainty visualization. The experiments are framed from two conceptual perspectives. First, a typology of uncertainty is used to delineate kinds of uncertainty matched with space, time, and attribute components of data. Second, concepts from visual semiotics are applied to characterize the kind of visual signification that is appropriate for representing those different categories of uncertainty. This framework guided the two experiments reported here. The first addresses representation intuitiveness, considering both visual variables and iconicity of representation. The second addresses relative performance of the most intuitive abstract and iconic representations of uncertainty on a map reading task. Combined results suggest initial guidelines for representing uncertainty and discussion focuses on practical applicability of results.

Visualizing uncertainty about the future

We are all faced with uncertainty about the future, but we can get the measure of some uncertainties in terms of probabilities. Probabilities are notoriously difficult to communicate effectively to lay audiences, and in this review we examine current practice for communicating uncertainties visually, using examples drawn from sport, weather, climate, health, economics, and politics. Despite the burgeoning interest in infographics, there is limited experimental evidence on how different types of visualizations are processed and understood, although the effectiveness of some graphics clearly depends on the relative numeracy of an audience. Fortunately, it is increasingly easy to present data in the form of interactive visualizations and in multiple types of representation that can be adjusted to user needs and capabilities. Nonetheless, communicating deeper uncertainties resulting from incomplete or disputed knowledge--or from essential indeterminacy about the future--remains a challenge.

Communication of uncertainty regarding individualized cancer risk estimates: effects and influential factors

OBJECTIVE

To examine the effects of communicating uncertainty regarding individualized colorectal cancer risk estimates and to identify factors that influence these effects.

METHODS

Two Web-based experiments were conducted, in which adults aged 40 years and older were provided with hypothetical individualized colorectal cancer risk estimates differing in the extent and representation of expressed uncertainty. The uncertainty consisted of imprecision (otherwise known as "ambiguity") of the risk estimates and was communicated using different representations of confidence intervals. Experiment 1 (n = 240) tested the effects of ambiguity (confidence interval v. point estimate) and representational format (textual v. visual) on cancer risk perceptions and worry. Potential effect modifiers, including personality type (optimism), numeracy, and the information's perceived credibility, were examined, along with the influence of communicating uncertainty on responses to comparative risk information. Experiment 2 (n = 135) tested enhanced representations of ambiguity that incorporated supplemental textual and visual depictions.

RESULTS

Communicating uncertainty led to heightened cancer-related worry in participants, exemplifying the phenomenon of "ambiguity aversion." This effect was moderated by representational format and dispositional optimism; textual (v. visual) format and low (v. high) optimism were associated with greater ambiguity aversion. However, when enhanced representations were used to communicate uncertainty, textual and visual formats showed similar effects. Both the communication of uncertainty and use of the visual format diminished the influence of comparative risk information on risk perceptions.

CONCLUSIONS

The communication of uncertainty regarding cancer risk estimates has complex effects, which include heightening cancer-related worry-consistent with ambiguity aversion-and diminishing the influence of comparative risk information on risk perceptions. These responses are influenced by representational format and personality type, and the influence of format appears to be modifiable and content dependent.

The effect of graphics on environmental health risk beliefs, emotions, behavioral intentions, and recall

Lay people have difficulty understanding the meaning of environmental health risk information. Visual images can use features that leverage visual perception capabilities and semiotic conventions to promote meaningful comprehension. Such evidence-based features were employed to develop two images of a color-coded visual scale to convey drinking water test results. The effect of these images and a typical alphanumeric (AN) lab report were explored in a repeated measures randomized trial among 261 undergraduates. Outcome measures included risk beliefs, emotions, personal safety threshold, mitigation intentions, the durability of beliefs and intentions over time, and test result recall. The plain image conveyed the strongest risk message overall, likely due to increased visual salience. The more detailed graded image conveyed a stronger message than the AN format only for females. Images only prompted meaningful risk reduction intentions among participants with optimistically biased safety threshold beliefs. Fuzzy trace theory supported some findings as follow. Images appeared to promote the consolidation of beliefs over time from an initial meaning of safety to an integrated meaning of safety and health risk; emotion potentially shaped this process. Although the AN report fostered more accurate recall, images were related to more appropriate beliefs and intentions at both time points. Findings hinted at the potential for images to prompt appropriate beliefs independent of accurate factual knowledge. Overall, results indicate that images facilitated meaningful comprehension of environmental health risk information and suggest foci for further research.

Effect of risk ladder format on risk perception in high- and low-numerate individuals

Utilizing a random sample from the general population (N= 257), we examined the effect of the radon risk ladder on risk perception, as qualified by respondents' numeracy. The radon risk ladder provides comparative risk information about the radon equivalent of smoking risk. We compared a risk ladder providing smoking risk information with a risk ladder not providing this information. A 2 (numeracy; high, low) x 3 (risk level; high, medium, low) x 2 (smoking risk comparison: with/without) between subjects experimental design was used. A significant (p < 0.045) three-way interaction between format, risk level, and numeracy was identified. Participants with low numeracy skills, as well as participants with high numeracy skills, generally distinguished between low, medium, and high risk levels when the risk ladder with comparative smoking risk information was presented. When the risk ladder without the comparative information about the smoking risk was presented, low-numerate individuals differentiated between risk levels to a much lesser extent than high-numerate individuals did. These results provide empirical evidence that the risk ladder can be a useful tool in enabling people to interpret various risk levels. Additionally, these results allow us to conclude that providing comparative information within a risk ladder is particularly helpful to the understanding of different risk levels by people with low numeracy skills.