11. The computer readable and writeable recording medium of claim 7 , wherein the method for creating the related term table comprises: analyzing each of the document snippets to list a plurality of the potential terms for each of the document snippets; and performing a weighting calculation for determining the keyterms corresponding to each of the document snippets from the potential terms of each of the document snippets.
7. A computer readable and writeable recording medium for storing a program for instantly expanding a keyterm, wherein the program for instantly expanding a keyterm executes a plurality of instructions comprising: receiving a query term; according to the query term, performing a data search process by using a plurality of search engines; obtaining a plurality of document snippets related to the query term from each of the search engines, wherein each of the document snippets contains at least a sentence; analyzing each of the document snippets to create a related term table, wherein, for each of the document snippets in the related term table, a plurality of keyterms appeared in each of the document snippets are listed and each of the keyterms possesses a semantic meaning; according to a position relationship between the query term and each of the keyterms in each of the document snippets, performing a correlation calculation for giving each of the keyterms in each of the document snippets a correlation value; performing a semantic merging process to merge the correlation values of the keyterms with the same semantic meaning throughout the document snippets to be a correlation indicator, wherein the semantic merging process further comprises: performing a semantic centroid calculation for calculating the correlation values of keyterms having the same semantic meaning throughout the document snippets to be a plurality of centroid values respectively; and performing a normalization process for normalizing the centroid values to be a plurality of correlation indicators respectively, wherein a sum of the correlation indicators is equal to 1; and according to the correlation indicator for each of the keyterms, determining portions of the keyterms to be a keyterm set of the query term.