October 3, 2018

On October 3, 2018, The Federal Emergency Management Agency (FEMA), in coordination with the Federal Communications Commission (FCC), conducted a nationwide test of the Wireless Emergency Alerts (WEA) and Emergency Alert System (EAS).

Phones are lighting up in pockets and purses nationwide. Adopting new technology to send alerts to wireless devices is a major step forward, and a major change, in the way that the government warns the public during emergencies.

Alerts sent to phones — How do people react?

According to CU Denver researcher Dr. Hamilton Bean, an associate professor in the Communication Department, milling behavior (searching for more information about a threat prior to acting when a wireless emergency alert is received) is common, and it can be harmful when it delays the message recipient from acting to avoid an imminent threat.

Bean has led or participated in some of the most comprehensive and current research to-date about WEA technology.  Here are quotes and analysis of the research findings.

Dr. Hamilton Bean, Associate Professor, Communication Department


  • “While we have many decades of research concerning how to effectively alert and warn people via mass media like television and radio, mobile devices create new opportunities and new questions. Many of the earlier research findings concerning how people understand and respond to messages still apply, but mobile technology provides new affordances and constraints that researchers are just beginning to investigate.”


  • “What the emerging research record indicates is that WEA messages can currently provide enabled device users with a geotargeted alert and warning message when facing an imminent threat, thereby reaching people at new times and places (i.e., when sleeping, hiking, traveling, etc.)”


  • “Perhaps the most significant finding, which is both a benefit and challenge of WEA messages, is their role in sparking milling behavior, which is “the process of seeking information from others regarding alert and warning messages.”


  • “Researchers consistently find that WEA messages grab attention and spur people to seek additional and confirming information. However, depending on the nature of a hazard, that response delay, that milling or searching behavior, can result in harm.”


  • “For rapid onset emergencies, such as a nuclear or radiological event, the goal is to compel people to action quickly. So far, research suggest that WEA messages cannot include information to uniformly and predictably overcome people’s preconceived notions of hazards and/or reduce milling behavior.”


Background and Research:

Dr. Bean served as the lead qualitative researcher on the Comprehensive Testing of Imminent Threat Public Messages for Mobile Devices Project (MDP) funded by the U.S. Department of Homeland Security (2012-2016). (https://nca.tandfonline.com/doi/abs/10.1080/15358593.2015.1014402#.W7UJ1WhKhPY)

Portions of these project were featured in a recent National Academies report: Emergency Alert and Warning Systems: Current Knowledge and Future Research Directions. The report synthesizes several other DHS-funded research projects concerning the WEA system. The report is the most up-to-date and comprehensive summary of WEA-related research available.

MDP research has been cited in recent FCC Rulemakings concerning the WEA system. A Wireless Emergency Alert, or WEA, is a 90-character first alert message (sent via cellular broadcast technology). It is a message accompanied by distinctive audible tone and vibration. Although these messages are currently only 90 characters long, 360 characters are now permitted by the FCC, and the capability to send longer messages must be implemented by participating wireless service providers by May 1, 2019.

WEA messages are geotargeted by the alert originator (which is often a local, regional, or state emergency response agency), but they are distributed by commercial wireless providers. Effective November 30, 2019, WEA messages must be sent with more than 0.1 mile overshoot in a particular geographic area. The message content topics and order are generally set as hazard, location, time, protective action, source.

Bean and colleagues began studying WEA messages in 2012 as the system was just being rolled out across the United States. The findings from MDP have been published in several studies.

One is “Disaster Warnings in Your Pocket: How Audiences Interpret Mobile Alerts for an Unfamiliar Hazard,” which focused on the qualitative data related to mock 90-character WEA messages and 140-character tweets.(https://onlinelibrary.wiley.com/doi/abs/10.1111/1468-5973.12108)

Not surprisingly, “… while participants offered a wide variety of interpretations, WEAs and tweets were often deemed confusing, difficult to believe and impersonal. Participants also consistently found WEAs and tweets to be fear inducing and uninformative.”

A second article, led by Dr. Michele Wood and Dr. Dennis Mileti, is “Milling and Public Warning.” (http://journals.sagepub.com/doi/abs/10.1177/0013916517709561) This study integrated MDP’s qualitative and quantitative data, as well as focused on longer messages of 1,380 characters. A key finding was that relative to shorter messages, longer public warning messages reduced people’s inclination to search for and confirm information, thereby shortening warning response delay.

Messages can include vibration, sound, and light for those with disabilities (but adjustments are warranted). They can include a hyperlink for additional information (this has been permitted since 2016, but current use is unclear).

To help improve the WEA system, the FCC is considering including multimedia content without a hyperlink (such as an embedded map or photo), providing multilingual messages (Spanish language ability already must be implemented by May 1, 2019), and more easily integrate WEA with social media.

Portions of these project were featured in a recent National Academies report: Emergency Alert and Warning Systems: Current Knowledge and Future Research Directions. The report synthesizes several other DHS-funded research.

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