Date of Award

Spring 2023

Document Type


Degree Name

Doctor of Science (DSc) in Emergency Management


Emergency Management & Public Administration

Committee Chair

Shih-Kai Huang


The unique disaster, tornado, causes significant damage and casualties in the US every year, and tornado warnings are crucial to helping people take protective action and reduce the negative impact, especially in an unfamiliar situation. It is important for authorities to better understand how households in low-risk areas rely on information, perceive risk, and make protective action decisions because tornadoes can occur in many geographic locations and might cause significant damage. However, tornado information search behavior and the dynamic decision-making process are not well understood in the existing literature. Therefore, this study aimed to explore the effect of the interaction between couples on their information search behaviors and protective action decisions. To better understand this issue, 68 couples who were living in the Seattle (WA) metropolitan area, known for being at low risk of experiencing tornadoes, were recruited to respond to an escalating tornado scenario (Alerts 1 to 5). An experiment, using the DynaSearch computer program, was conducted to get insight into couples’ decision-making processes in terms of individual and joint decision-making. DynaSearch, using internet web browsers, was set up to display the severe weather scenario (5-stage alerts) on Information Screens and ask questions on Questionnaire Screens. To investigate couples’ information preferences, DynaSearch displayed four types of graphic information and eight kinds of textual information for each alert. DynaSearch also recorded the mouse click counts and click duration when participants searched for information. Additionally, to examine their responses when faced with the threat, participants reported the likelihood of taking eight types of actions after each alert.

The results showed that the differences in risk perception between couples and individuals were not significant in an unfamiliar event. Yet, the interaction between couples has an impact on their responses to the threat. Couples and male individuals were less likely to leave home or seek a public shelter under a tornado warning compared to female individuals. Additionally, risk information comprehension and tornado knowledge were positively correlated with staying at home and not evacuating (i.e., perceiving the need for immediate protective action rather than potentially putting oneself in harm’s way) while under a tornado warning. Moreover, compared to tornado risk maps, people preferred textual information (e.g., protective action recommendations, potential impact, hazards, storm location) when faced with an unfamiliar situation. Overall, these findings can inform authorities and meteorologists in understanding how households in low-risk areas search for tornado information, their preferences, and the different responses based on decision-making conditions.


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