The Post-Alert Lexicon: A Multiphased Study to Develop Content for Post-Alert Messages

Using a multiphased, mixed methods approach, grounded in theory on alerts and warnings, the Post-Alert Lexicon serves as a companion to the Warning Lexicon to provide evidence-based guidance on how to construct a postalert message for 45 hazards and missing person events. We draw from the results of quantitative content analyses of a census of postalert messages issued as Wireless Emergency Alerts from 2012 to 2022, and public message testing experiments for three hazard types (wildfire, earthquake, and bomb threat), to find that a focus on hazard resolution and public action, rather than the commonly employed language of “all clear,” increases message understanding, personalization, and decision making and positively affects public trust in the message sender. The Post-Alert Lexicon incorporates the language used by alerting authorities into consistent and simplified word sets used to convey hazard resolution and provide new safety instructions. Lexicon contents were reviewed by subject matter experts and developed into message templates that provide the contents necessary to relay that a hazardous situation has been resolved and that people may conclude, resume, or return to their former activities. The template workflow for each postalert message offers editable content to design consistent, behavioral-driven messages with a focus on resolution and action (i.e., information that is usable by message receivers). By using the Post Alert Lexicon, public safety communicators can help to reduce the uncertainty that comes with an initial alert and close the communication loop, thereby increasing organizational credibility and transparency.