Term of Award

Summer 2015

Degree Name

Master of Science in Experimental Psychology (M.S.)

Document Type and Release Option

Thesis (open access)

Copyright Statement / License for Reuse

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.


Department of Psychology

Committee Chair

Lawrence Locker, Jr.

Committee Member 1

Karen Naufel

Committee Member 2

Ty Boyer


There are many unnecessary deaths from tornadoes every year (NOAA.org, 2013). Although there have been great advancements in tornado warning systems (Coleman, Knupp, Spann, Elliot, & Peters, 2010), more changes to systems could be made to motivate people to take action in preparation for tornadoes (Brotzge & Donner, 2013). Protection motivation theory outlines the process by which we assess threats and decide whether or not preventative actions are worth performing. If the threat is perceived as severe enough and the preventative actions are seen as capable of mitigating the threat, the individual is motivated to act (Rogers, 2000). One means by which to enhance the efficacy of weather warnings is through the use of visual imagery. Research has shown that pictures are more easily remembered than words (e.g., Jenkins, Neale & Deno, 1967), and that the addition of picture descriptions or “pictorials” to public safety warnings increases the comprehension and perceptions of risks (Wogalter & Laughery 1997; Severson & Henriques, 2009 respectively). However, the effect of pictures varies depending on many factors including how closely the pictures are perceptually linked to the text and how the picture relates to the target audience (Houts, Doak, Doak, & Loscalzo, 2006). In the current study, we examined the influence of visual imagery in the context of tornado warnings. Specifically, we examined the effects of different tornado warnings on perceptions of susceptibility, response efficacy, and self-efficacy. The warnings varied by whether or not they contained pictures of damage, pictures of preparations, or no pictures. The pictures also varied by tornado category (F2 or F4). F4 warnings were expected to elicit greater susceptibility than F2 warnings. Warnings with pictures of damage were expected to elicit higher susceptibility in an interactive effect in the context of F4 warnings than those with preparation or no pictures. Warnings with preparation pictures were expected to elicit greater levels of efficacy than those with damage or no pictures. Warnings with either type of picture were expected to elicit higher levels of comprehension. The results revealed that participants who viewed the F4 warnings perceived themselves to be more at risk than those who viewed the F2 warnings. There was an effect of both damage and preparation pictures on response efficacy of actions recommended in the event of a tornado, such that those who viewed warnings with either type of picture rated the recommended actions as more efficacious that those who simply saw a text warning. Also, in this study a trend was observed such that participants who viewed more severe tornado warnings (i.e., F4) rated themselves as more efficacious (self-efficacy) in the event of a tornado than those who viewed less severe tornado warnings (i.e., F2). Also of importance, those who viewed the F4 warnings had overall lower comprehension of damage or susceptibility related information when compared to those who viewed F2 warnings. Implications of results and future directions are discussed.

Research Data and Supplementary Material