Earthquake early warning message testing: Visual attention, behavioral responses, and message perceptions

Earthquake early warning (EEW) systems have the potential to facilitate the delivery of lifesaving information to individuals in the path of damaging shaking before it reaches them. While much attention has been devoted to measuring the technological feasibility in terms of reach, accuracy, and latency of EEW message delivery, one additional aspect that merits considerable attention is the effectiveness of alerts themselves; do they deliver actionable information that can lead to protective actions taken by message receivers? In this project, we investigated individual responses to a simulated EEW message in a laboratory environment. We employed eye-tracking technology to evaluate visual attention to specific message features; measured behavioral responses to the EEW message (i.e., the participants' ability to perform the recommended actions correctly); and collected self-reported perceptions of the messages (including participants’ intent to act in response to future EEW messages). We manipulated two variables selected to be likely to affect visual attention, behavioral responses, and message perceptions: 1) prior exposure to the relevant protective actions, and 2) the presence of informational icons about the protective actions within the message. We found that prior exposure to protective actions is the strongest predictor of behavioral response and message perceptions; however, the inclusion of informational icons had little effect on our results, suggesting a need for further research testing. The results of this study should inform recommendations for message design and public education and training, all of which are critical to the success of EEW.