for a message exchange to be successful, the sender and the recipient must have agreed on a vocabulary that avoids ambiguity. for example, the word "hedge" can mean completely different things based on the context. in botany a hedge is a row of shrubs or trees that make a barrier or form a border. in finance, a hedge is an investment made to reduce the risk of another investment. in linguistics a hedge is a word or set of words that make other words less important. without information it is therefore very difficult to know which "hedge" is really meant by the speaker.