4. A computer system for building concept knowledge from a machine-readable dictionary for use by a search engine to facilitate quick and accurate information retrieval, comprising a machine-readable dictionary including a plurality of words in a first language and a plurality of corresponding translated words in a second language, and a plurality of words in the second language and a plurality of corresponding translated words in the first language; an input device for inputting a seed word; a translator for translating a word into a plurality of translated words in a desired language by looking up said machine-readable dictionary; a decision making means for controlling said translator to translate the seed word into a plurality of translated words in the second language and to translate each of the translated words in second language into a plurality of translated words in the first language respectively as words of the concept knowledge; a synonym library for storing synonymous words of each translated word in the first language and in the second language; a frequency calculator for calculating the number of times each translated word occurs during said translating; an evaluation unit for ranking said translated words in the first language and in the second language based on the synonym library and the frequency calculator; a word browser for presenting said ranked words to a user; a word selecting unit for allowing said user to select desired words among said ranked words and to delete irrelevant words among said ranked words; and means for providing said selected desired words to said search engine to perform knowledge-based information retrieval instead of keyword-based information retrieval.
7. The computer system for building concept knowledge from a machine-readable dictionary for use by a search engine to facilitate quick and accurate information retrieval in accordance with claim 4 , wherein said machine-readable dictionary contains words in more than two languages and corresponding relations thereamong; wherein said decision making means repeat the translation of the translated words among said plurality of languages until a predefined number of times is reached, or a predefined number of the translated words are obtained, or all of the translated words in the first language have been translated as seed words.