He is the author of the Prentice-Hall text, The Practice of Public Relations . But, since the people you work for always want them, you've got to go through with the agony of setting them up and pulling them off. A press conference, formally defined, is the convening of the media for a specific announcement.
Press conferences can flop resoundingly.
First of all, reporters hate 'em. Journalists want to be first with the news. Since everyone attending gets the same information at the same time, the possibility of reportorial initiative is lost. Journalists are also busy with daily deadlines. So the necessity of schlepping cross-town to a meeting that may contain little news is often a royal pain in the butt.