Cova, Thomas J.; Dennison, Philip E.; Li, Dapeng; Drews, Frank A.; Siebeneck, Laura K.; Lindell, Michael K. (2017). Warning Triggers in Environmental Hazards: Who Should Be Warned to Do What and When? Risk Analysis, 37(4), 601 – 611.
View Publication
Abstract
Determining the most effective public warnings to issue during a hazardous environmental event is a complex problem. Three primary questions need to be answered: Who should take protective action? What is the best action? and When should this action be initiated? Warning triggers provide a proactive means for emergency managers to simultaneously answer these questions by recommending that a target group take a specified protective action if a preset environmental trigger condition occurs (e.g., warn a community to evacuate if a wildfire crosses a proximal ridgeline). Triggers are used to warn the public across a wide variety of environmental hazards, and an improved understanding of their nature and role promises to: (1) advance protective action theory by unifying the natural, built, and social themes in hazards research into one framework, (2) reveal important information about emergency managers' risk perception, situational awareness, and threat assessment regarding threat behavior and public response, and (3) advance spatiotemporal models for representing the geography and timing of disaster warning and response (i.e., a coupled natural-built-social system). We provide an overview and research agenda designed to advance our understanding and modeling of warning triggers.
Keywords
Situation Awareness; Evacuation; Model; Management; Simulation; Decisions; Vehicles; Support; Systems; Hazards; Protective Actions; Warning Systems; Emergency Communications Systems; Disasters; Emergency Preparedness; Environmental Hazards; Environmental Conditions; Public Concern; Risk Perception; Emergency Management; Situational Awareness; Information Management; Geography; Emergency Warning Programs; Wildfires; Action; Risk Assessment; Timing; Warnings
Huang, Shih-kai; Wu, Hao-che; Lindell, Michael K.; Wei, Hung-lung; Samuelson, Charles D. (2017). Perceptions, Behavioral Expectations, and Implementation Timing for Response Actions in a Hurricane Emergency. Natural Hazards, 88(1), 533 – 558.
View Publication
Abstract
This study examined the perceived attributes, behavioral expectations, and expected implementation timing of 11 organizational emergency response actions for hurricane emergencies. The perceived attributes of the hurricane response actions were characterized by two hazard-related attributes (effectiveness for person protection and property protection) and five resource-related attributes (financial costs, required knowledge/skill, required equipment, required time/effort, and required cooperation). A total of 155 introductory psychology students responded to a hypothetical scenario involving an approaching Category 4 hurricane. The data collected in this study explain previous findings of untimely protective action decision making. Specifically, these data reveal distinctly different patterns for the expected implementation of preparatory actions and evacuation recommendations. Participants used the hazard-related and resource-related attributes to differentiate among the response actions and the expected timing of implementation. Moreover, participants' behavioral expectations and expected implementation timing for the response actions were most strongly correlated with those actions' effectiveness for person protection. Finally, participants reported evacuation implementation times that were consistent with a phased evacuation strategy in which risk areas are evacuated in order of their proximity to the coast. However, the late initiation of evacuation in risk areas closest to the coast could lead to very late evacuation of risk areas farther inland.
Keywords
Action Decision-making; Interrater Agreement; Evacuation; Time; People; Preparatory Actions; Response Action Attributes; Trigger Timing; Hurricane; Psychology; Hurricanes; Costs; Emergency Response; Data; Proximity; Coastal Environments; Hazards; Decision Making; Emergencies; Emergency Preparedness; Risk; Equipment Costs; Cooperation; Protection; Equipment; Evacuations & Rescues; Behavioral Psychology; Time Measurement
Lindell, Michael K.; Mumpower, Jeryl L.; Huang, Shih-kai; Wu, Hao-che; Samuelson, Charles D.; Wei, Hung-lung. (2017). Perceptions of Protective Actions for a Water Contamination Emergency. Journal Of Risk Research, 20(7), 887 – 908.
View Publication
Abstract
Local authorities who believe their water systems are contaminated need to warn those at risk to take protective actions. In the past, such efforts have often achieved only partial success in preventing people from deciding to continue consumption of contaminated drinking water. To examine the possible antecedents of decisions to comply with water consumption advisories, this study examined 110 Boston residents' actual protective actions and 203 Texas students' expected protective actions; their perceptions of three protective actions on seven attributes; and their risk perceptions, water contamination experience, facilitating conditions, and demographic characteristics. The profiles of the protective actions for the hazard-related and resource-related attributes suggest reasons why people preferred to use bottled water rather than boil or personally chlorinate water. In particular, perceived effectiveness in protecting health was the most important correlate of protective action, which means that a protective action can have a high level of implementation even though it has poor ratings on other attributes such as cost. In addition, this study indicates public health officials may also need to address people's misconceptions about the hazard-related and resource-related attributes of any relevant protective actions. Finally, consistent with an extensive body of previous research, students were similar to residents in many important respects even though were some statistically significant differences.
Keywords
Action Decision-model; Hazard Adjustments; College-students; Plant Accident; Risks; Metaanalysis; Triviality; Attitudes; Behavior; Adoption; Water Contamination; Risk Perception; Protective Action; Protective Action Attributes; Student Vs; Population Samples
Doyle, Emma E. H.; Mcclure, John; Potter, Sally H.; Becker, Julia S.; Johnston, David M.; Lindell, Michael K.; Johal, Sarbjit; Fraser, Stuart A.; Coomer, Maureen A. (2018). Motivations to Prepare After the 2013 Cook Strait Earthquake, N.Z. International Journal Of Disaster Risk Reduction, 31, 637 – 649.
View Publication
Abstract
We investigated responses to the 2013 Cook Strait earthquake sequence, New Zealand. This included two foreshocks (M5.7 and M5.8) and a mainshock doublet pair: M6.5 Cook Strait (CS) earthquake on 21st July and M6.6 Lake Grassmere (LG) earthquake on Friday 16th August. We examined relationships between preparedness, experience and beliefs during the earthquakes, as well as concern and subsequent preparedness actions. Results indicate that earthquake characteristics (e.g., time, location) influence the types of preparedness actions. While there was a reduction in new actions from the first mainshock doublet earthquake (CS) to the second (LG), there were a large number of participants who reviewed or revisited their prior actions, related to their beliefs about impacts, in a form of problem-focused targeted action. Females took more actions than did males, and had a higher rate of immediate aftershock concern. For all participants, concern was greater after the CS earthquake than after the full earthquake sequence, supporting the findings of McClure et al. (2016) that there is a limited window after an event to maximise the opportunity for effective preparedness initiatives. Findings additionally suggest that such post-earthquake preparedness initiatives should consider the impacts that elicited the highest rate of concern in an event, and should tailor messages towards them. While this earthquake sequence resulted in low levels of impact and damage, it presents interesting findings regarding how disruption (in lieu of major damage) influences earthquake preparedness actions, which is particularly important to understand in highly active regions often exposed to smaller impact events.
Keywords
Seismic Hazard Adjustments; Risk Communication; Decision-making; Natural Hazards; Unrealistic Optimism; Different Regions; Volcanic Crisis; Perception; Disaster; Behavior; Earthquakes; Preparedness; Beliefs; Concern; Actions; Gender
Jon, Ihnji; Huang, Shih-kai; Lindell, Michael K. (2018). Perceptions and Reactions to Tornado Warning Polygons: Would a Gradient Polygon Be Useful? International Journal Of Disaster Risk Reduction, 30, 132 – 144.
View Publication
Abstract
To better understand people's interpretations of National Weather Service's tornado warning polygons, 145 participants were shown 22 hypothetical scenarios in one of four displays-deterministic polygon, deterministic polygon + radar image, gradient polygon, and gradient polygon + radar image. Participants judged each polygon's numerical strike probability (p(s)) and reported the likelihood of taking seven different response actions. The deterministic polygon display produced p(s) that were highest at the polygon's centroid and declined in all directions from there. The deterministic polygon + radar display, the gradient polygon display, and the gradient polygon + radar display produced p(s) that were high at the polygon's centroid and also at its edge nearest the tornadic storm cell. Overall, p(s) values were negatively related to resuming normal activities, but positively correlated with expectations of resuming normal activities, seeking information from social sources, seeking shelter, and evacuating by car. These results replicate the finding that participants make more appropriate p(s) judgments when polygons are presented in their natural context of radar images than when the polygons are presented in isolation and that gradient displays appear to provide no appreciable benefit. The fact that p(s) judgments had moderately positive correlations with both sheltering (a generally appropriate response) and evacuation (a generally inappropriate response) provides experimental confirmation that people threatened by actual tornadoes are conflicted about which protective action to take.
Keywords
Protective Action; Uncertainty; Risk; Psychology; Casualties; Tornado Warning Polygons; Risk Perceptions; Protective Actions
Jon, Ihnji; Huang, Shih-Kai; Lindell, Michael K. (2019). Perceptions and Expected Immediate Reactions to Severe Storm Displays. Risk Analysis, 39(1), 274 – 290.
View Publication
Abstract
The National Weather Service has adopted warning polygons that more specifically indicate the risk area than its previous county-wide warnings. However, these polygons are not defined in terms of numerical strike probabilities (p(s)). To better understand people's interpretations of warning polygons, 167 participants were shown 23 hypothetical scenarios in one of three information conditions-polygon-only (Condition A), polygon + tornadic storm cell (Condition B), and polygon + tornadic storm cell + flanking nontornadic storm cells (Condition C). Participants judged each polygon's p(s) and reported the likelihood of taking nine different response actions. The polygon-only condition replicated the results of previous studies; p(s) was highest at the polygon's centroid and declined in all directions from there. The two conditions displaying storm cells differed from the polygon-only condition only in having p(s) just as high at the polygon's edge nearest the storm cell as at its centroid. Overall, p(s) values were positively correlated with expectations of continuing normal activities, seeking information from social sources, seeking shelter, and evacuating by car. These results indicate that participants make more appropriate p(s) judgments when polygons are presented in their natural context of radar displays than when they are presented in isolation. However, the fact that p(s) judgments had moderately positive correlations with both sheltering (a generally appropriate response) and evacuation (a generally inappropriate response) suggests that experiment participants experience the same ambivalence about these two protective actions as people threatened by actual tornadoes.
Keywords
Decision-making; Tornado; Risk; Communication; Numeracy; Residents; Shelter; Events; Protective Actions; Risk Perceptions; Tornado Warning Polygons; Judgments; Tornadoes; Meteorological Services; Storms; Lymphocytes B; Polygons; Emergency Warning Programs; Evacuation; Displays; Inappropriateness; Weather; Warnings; Conditions; Ambivalence
Lindell, Michael K.; Arlikatti, Sudha; Huang, Shih-kai. (2019). Immediate Behavioral Response to the June 17, 2013 Flash Floods in Uttarakhand, North India. International Journal Of Disaster Risk Reduction, 34, 129 – 146.
View Publication
Abstract
The 2013 Uttarakhand flash flood was such a surprise for those at risk that the predominant source of information for their risk was environmental cues and, secondarily, peer warnings rather than official warnings. Of those who received warnings, few received information other than the identity of the flood threat. A survey of 316 survivors found that most people's first response was to immediately evacuate but some stayed to receive additional information, confirm their warnings, or engage in evacuation preparations. Unfortunately, engaging in these milling behaviors necessarily delayed their final evacuations. Mediation analysis revealed that psychological reactions mediated the relationship between information sources and behavioral responses. Further analyses revealed that immediate evacuation and evacuation delay were both predicted best by information search and positive affect, but correlation analyses indicated that a number of other models were also plausible. Final evacuation was best predicted by immediate evacuation and, to a significantly lesser extent, household together. Overall, results suggest that the Protective Action Decision Model (PADM) should be considered a useful framework for examining household responses to flash floods in developing countries like India. It supports the conclusion that a household's first warning source is a function of two distinct detection and dissemination systems within a community-an official system and an informal system. However, it fails to capture what pre-impact emergency preparedness entails for rapid onset events in a developing country context. Further research is needed to determine the relative importance of situational and cultural characteristics in producing these observed differences.
Keywords
Risk Perception; Mental Models; Warnings; Evacuation; Disaster; Tsunami; Communication; Earthquake; Beliefs; Hazard; Flash Flood; Warning; Psychological Reactions; India
Lindell, Michael K.; House, Donald H.; Gestring, Jordan; Wu, Hao-Che. (2019). A Tutorial on Dynasearch: A Web-Based System for Collecting Process-Tracing Data in Dynamic Decision Tasks. Behavior Research Methods, 51(6), 2646 – 2660.
View Publication
Abstract
This tutorial describes DynaSearch, a Web-based system that supports process-tracing experiments on coupled-system dynamic decision-making tasks. A major need in these tasks is to examine the process by which decision makers search over a succession of situation reports for the information they need in order to make response decisions. DynaSearch provides researchers with the ability to construct and administer Web-based experiments containing both between- and within-subjects factors. Information search pages record participants' acquisition of verbal, numeric, and graphic information. Questionnaire pages query participants' recall of information, inferences from that information, and decisions about appropriate response actions. Experimenters can access this information in an online viewer to verify satisfactory task completion and can download the data in comma-separated text files that can be imported into statistical analysis packages.
Keywords
Downloading; Text Files; Tasks; Access To Information; Statistics; Dynamic Decision Making; Process Tracing; Web-based Experiments; Information Search; Human-behavior; Eye-tracking; Choice; Expectations; Strategies; Mousetrap; Software; Time
Doyle, Emma E. H.; McClure, John; Potter, Sally H.; Lindell, Michael K.; Becker, Julia S.; Fraser, Stuart A.; Johnston, David M. (2020). Interpretations of Aftershock Advice and Probabilities After the 2013 Cook Strait Earthquakes, Aotearoa New Zealand. International Journal Of Disaster Risk Reduction, 49.
View Publication
Abstract
Probabilistic statements can be a valuable tool for natural hazard risk communication, including forecasts. However, individuals often have a poor understanding of such probabilistic forecasts caused by them distorting their interpretations of event likelihoods towards the end of the time window and discounting the risk today. We investigated the use of an 'anchoring' time statement to mitigate this bias via an opportunistic survey run after the 2013 Cook Strait earthquakes, near Wellington, New Zealand. Participants rated their interpretations of likelihoods for an immediate aftershock forecast, and for an earthquake in the future. We explored the influence of aftershock and information concern, emotions and felt shaking, gender and education, as well as preparedness actions. The anchoring time window statement mitigated the skew in interpretations for the short (24 h to within 1 week) aftershock forecast statement. However, the skew still existed for the longer future earthquake forecast (7 days to within 1 year). We also found that heightened sensory experience (felt shaking) or emotional reactions (nervousness, fear, alertness) during the earthquakes was associated with an increase in the perceived likelihoods of future events. Gender was found to significantly influence results, with females rating higher levels of information concern and anxiety, and recording higher perceived likelihoods for the immediate aftershock forecast. Findings, including the importance of 'anchoring' time windows within a forecast to encourage immediate preparedness actions, support recommendations for effective crafting of these forecasts and warnings.
Keywords
False Discovery Rate; Risk Perceptions; Natural Hazards; Communication; Uncertainty; Model; Preparedness; Information; Experiences; Intentions; Likelihood; Probabilities; Forecasts; Earthquakes; Emotions; Concern; Gender; Actions
Lindell, Michael K.; Mumpower, Jeryl L.; Huang, Shih-kai; Wu, Hao-che; Samuelson, Charles D. (2015). Exposure Path Perceptions and Protective Actions in Biological Water Contamination Emergencies. Environmental Health Insights, 9, 13 – 21.
View Publication
Abstract
This study extends the Protective Action Decision Model, developed to address disaster warning responses in the context of natural hazards, to boil water advisories. The study examined 110 Boston residents' and 203 Texas students' expectations of getting sick through different exposure paths for contact with contaminated water. In addition, the study assessed respondents' actual implementation (for residents) or behavioral expectations (for students) of three different protective actions - bottled water, boiled water, and personally chlorinated water - as well as their demographic characteristics and previous experience with water contamination. The results indicate that people distinguish among the exposure paths, but the differences are small (one-third to one-half of the response scale). Nonetheless, the perceived risk from the exposure paths helps to explain why people are expected to consume (or actually consumed) bottled water rather than boiled or personally chlorinated water. Overall, these results indicate that local authorities should take care to communicate the relative risks of different exposure paths and should expect that people will respond to a boil water order primarily by consuming bottled water. Thus, they should make special efforts to increase supplies of bottled water in their communities during water contamination emergencies.
Keywords
Water Contamination; Exposure Paths; Risk Perception; Protective Action