摘要 : Effective warning messages should tell people what they should do, how they should do it, and how to maximize their health and safety. Guidance essentially delivers two types of information: 1) information that instructs people ab... 展开 Effective warning messages should tell people what they should do, how they should do it, and how to maximize their health and safety. Guidance essentially delivers two types of information: 1) information that instructs people about the actions to take in response to a threat and 2) information about how and why these recommended protective actions will reduce harm. However, recent research reported that while automated tornado warnings, sent by the National Weather Service Storm Prediction Center via the account @NWStornado on Twitter, included useful information about the location of the threat, the potential impacts, and populations at risk, they failed to provide content that would contribute to successful protective actions. In this experimental study we investigate how the inclusion and presentation of protective action guidance affects participant perceptions of a tornado warning message and their perceived ability to act upon the information (i.e., self- and response efficacy). We find that the inclusion of protective action guidance results an increase in the participants' understanding of the message, their ability to decide what to do, and their perceived self- and response efficacy. Knowing how to take action to protect oneself and believing the actions will make oneself safe are key motivators to taking action when faced with a significant threat. Future warning research should draw from other persuasive messaging and health behavior theories and should include self-efficacy and response efficacy as important causal factors. It should also look across additional hazards to determine if these outcomes differ by the length of forewarning and hazard type. SIGNIFICANCE STATEMENT: Tornadoes frequently pose an imminent threat to individuals, requiring quick decision-making. Warning messages can alert people to personal risk and protective actions that can limit loss and injury. How such messages are designed, including their content, style, and structure, can affect perceptual outcomes and behavioral intent. This study examines the effect of guidance information, that is, information instructing individuals about what to do to protect themselves, on their message perceptions. We find that tornado warning messages that include protective action information significantly increase individual perceptions of self-efficacy and response efficacy. At-risk publics, especially those faced with an unfamiliar hazard, benefit from risk communication that includes both threat information and protective action guidance to aid their decision-making about tornado response. 收起