Method for re-adjusting ranking of document to use user's profile and entropy

PURPOSE: A method for adjusting a ranking of a document using an entropy and a user profile is provided to increase the accuracy of searching by using an entropy value and a user profile according to probability information between a user query language and a subject of each document. CONSTITUTION: A user records a query language the user wants to search(S10). A volume of probability vector information of each word of the query language is calculated(S20). A user profile composed of keywords and frequencies of the keywords is designed for reflecting the user's preference in case that a ranking of a document is adjusted(S30). An entropy value between the user profile and index words extracted from the searching according to the user's subject is calculated(S40). After that, the ranking of the document is readjusted and outputted in order from the lowest entropy value calculated(S50).