In 1975, Ronald Rogers introduced a model that was revisited in 1983 for broader application in persuasive communication. Inspired by the work of Richard Lazarus in 1966 and Howard Leventhal in 1970, Rogers developed a danger appraisal model to better understand how fear is experienced. According to Karine Gallopel-Morvan, the PMM model can be summarized as follows: a frightening message is effective if it presents a sufficiently strong and probable threat, and if the proposed solution to protect oneself against it is considered effective and feasible. Without these four conditions, the message risks being ineffective and generating inappropriate reactions. For an illustration, see Industrial Strange.