Communicators - is there source a credible source, is health information coming from a professional or someone online.
Message - the message should have an emotional appeal and be two sided this may include, making people aware of the dangers of drinking but also acknowledging that it can provide pleasure.
Recipient - the intelligence levels of the recipient must be take into account.
Hovland - researched which was more persuasive academic journal or newspapers. The academic journal more easily swayed opinions.