15. An apparatus for searching for personalized content based on a user's comments about content within a database, the apparatus comprising: a computer system comprising a processor and a memory; a query receiving unit operating on the computer system and adapted receive a user query from the user, the user query including one or more terms; a preference analyzing unit operating on the computer system and adapted to analyze the user's comment, wherein the user query and the user's comment are made by the Same user and the user's comment is related to the user query, and the preference analyzing unit adapted unit adapted to extract the user's preferred terms, and wherein the user's comment is the user's assessment of each piece of content; wherein the preference analyzing unit extracts the users preferred terms based on the frequency of the terms included in the user's comment other information including the user's score on a corresponding piece of content; a query extending unit operating on the computer system and adapted to select at least one term from the extracted terms and to extend the user generating a query set which includes both the user query and the selected term, the query set including a plurality of terms used to request content from a database, the plurality of terms including both the one or more terms included in the user query and the selected term; and a content searching unit operating on the computer system and adapted to search for pieces of content based on the query set, and wherein the extracting of the users preferred terms comprises extracting the user's preferred terms using a TF-IDF technique.
17. The apparatus of claim 15 further comprising a search result providing unit that provides information about the pieces of content found by the content searching unit to a user terminal through which the user query is received.