As human understanding is largely metaphorical, what metaphor is, how children use it, and how they can be taught to use it more effectively are important educational concerns. A direct or indirect comparison between two apparently unlike things, metaphor consists of a topic, a vehicle of comparison, and ground--or traits--linking the topic and the vehicle. When the metaphor is interpreted, tension created by the comparison is resolved. A metaphor may be either context independent (a part sentence metaphor that is meaningless when interpreted literally) or context dependent (a whole sentence metaphor that may have a literal meaning in another context). Metaphors are evident in children's earliest speech and increase in frequency until the early elementary school years. With adolescence, metaphor usage again increases. Children's success at interpreting a metaphor seems to depend on the developmental cognitive stage controlling their thinking. First basing comparisons on physical similarities, children gradually begin to compare psychological and abstract qualities. Instructional procedures for developing student skill with metaphors include naming and classifying exercises, work with situational ambiguities, use of metonymy, and attention to the affect that a word's function in a sentence has on its meaning. (MM)