VOICE INTERACTION SYSTEM

PROBLEM TO BE SOLVED: To provide a voice interaction system which can perform efficient retrieval when a natural language including vague words of a user is inputted. SOLUTION: This system is equipped with: a command knowledge storage part 1 which stores command knowledge for converting a natural language into a command which is an expression consisting of intentions, items, and item values; a vague word dictionary storage part 6 storing a vague word dictionary containing vague words of the natural language which cannot be converted uniquely into item values, the items of the vague words, and meaning marks corresponding to the vague words; and a command conversion part 2 which generates pairs of items of vague words and meaning marks by replacing vague words included in a natural language that the user inputs with meaning marks corresponding to the vague words, and converts the inputted natural language into a command including the pairs of the items of the vague words and the meaning marks by referring to the command knowledge.