According to the present invention, a method for searching for information using the Web and a method for voice conversation using same involve generating a basic word vector for at least one of a provided user query and a language analysis result; using the basic word vector, searching a vector space database for a vector space corresponding to the basic word vector; searching, if a similarity between the basic word vector and the found vector space is lower than a preset reference, a vector space database for a vector space corresponding to an expanded word vector using the expanded word vector generated from the result of the Web search performed using at least one of the user query and the language analysis result; and searching for knowledge information on the basis of the vector space found in the basic searching step or the expanded searching step. Thus, improved research results may be provided in response to the user query.