Top to Bottom Theory: Top to bottom theory refers the process of analyzing a topic completely. Any people can think his processing of incoming discourse as the combination of (at least) two activities.
In first part, he can find out the meaning of the words, gradually structure of the sentence, phrase, clause, subject and verb etc. Then he should build up a composite meaning for the sentence. It may be as considered as bottom-up processing.
At the same time, on the basis of the context and the composite meaning of the sentences which have already processed, he should predict what the next sentence is most likely to mean. The process may be considered as top-down processing.
In some Artificial Intelligences, after reading a text we should find out the main theme of the text, the purpose of the text, the hidden voices of the author, the literary terms i.e. simile, metaphor, hyperbole, conceit, substitution, ellipsis, endophora and how far the text is related with our society etc. We should also find out cohesion, coherence and think about the reality of the topic and how far the author is succeeded.