Some authorities wish to persuasively define rhetoric as formal or public speeches, while others hold to a more traditional and broader definition pointing to the relevance of speech-act theory to support them. Central to speech-act theory is the illocutionary act (uttering at least one sentence of some language under certain conditions). Two effects are associated with each illocutionary act: an illocutionary effect is the reader's or listener's understanding or interpreting the illocutionary act, and the perlocutionary effect is a chain of effects dependent on the illocutionary effect. The problem of all communicators, not simply formal speech makers, is to speak or write clearly (illocutionary effectiveness) and to get people to believe their statements, answer their questions, and obey their commands (perlocutionary effectiveness). (TJ)