A Department of Homeland Security Center of Excellence led by the University of Maryland

A consortium of researchers dedicated to improving the understanding of the human causes and consequences of terrorism

Study shows longer emergency text alerts improve safety


Study shows longer emergency text alerts improve safety

A U.S. Department of Homeland Security (DHS)-sponsored START study shows lengthier text alerts during emergency situations helps citizens better prepare for risks ahead.

September 28, 2015Jessica Rivinius

Emergency text alerts with 280 characters, instead of the current 90, are more effective in improving public safety, according to a new study by the National Consortium for the Study of Terrorism and Responses to Terrorism (START).

In 280-character Wireless Emergency Alerts (WEA) messages, more information about the hazard, the recommended protective actions and the time until impact was included. With this added information, citizens better understood the threat at hand, what to do and how to do it. 

START utilized six focus groups and eight public experiments to investigate the optimized message content of WEAs. 

While the team’s prior research had shown that longer messages – up to 1,380 characters – could be more beneficial, today’s smart phones can only display up to 280 characters on a single screen. Additionally, several of the focus group participants described the 1,380-character messages as “too long.”

“Messages with 280 characters appear superior to 90- and 140-character messages in terms of participants’ stated understanding, belief, personalization, and intention to comply with protective-action guidance,” said Dr. Brooke Fisher Liu, the director of START’s Risk Communication & Resilience Program and professor of communication at the University of Maryland.

“We’re closer to finding the balance between communicating all needed information without overwhelming people with extraneous details,” Liu said.

Also playing a critical role in message effectiveness is the order of the content. In current messages, content appears as follows: hazard (what is happening), location (where it’s happening), time (when protective action should be taken), guidance (what protective action should be taken) and source (who is issuing the alert).

Participants who received a 280-character mock WEA message, with content in a new order – source, hazard, location, time and guidance – had significantly higher levels of message understanding and belief that it pertained to them than those who viewed a message with content ordered as in the current format.

“The message elements of ‘guidance’ and ‘time’ play major roles relative to other message elements when it comes helping people understand what’s happening and how to respond,” Liu said.

The team – Liu, Dr. Michele Wood (California State University, Fullerton), Dr. Hamilton Bean (University of Colorado Denver), Marcus Boyd (University of Maryland) – also found that message source played a role in establishing credibility. Well-known federal sources such as the National Oceanic and Atmospheric Administration (NOAA) and the National Weather Service (NWS) were the most effective sources in terms of credibility. 

The study also investigated additional elements that could be included in a WEA. For a 280-characater mock WEA, adding apps and hyperlinks appeared beneficial, whereas adding maps, did not. Both elements merit additional research.

The research was supported by the DHS Science and Technology Directorate, First Responders Group, Office for Interoperability and Compatibility, Wireless Emergency Alerts (WEA) Research, Development, Test and Evaluation (RDT&E) Program.

The full report, “Comprehensive Testing of Imminent Threat Public Messages for Mobile Devices: Updated Findings,” is available at FirstResponder.gov at this link.