Object data is stored in association with a plurality of attribute words categorized
according to sentence elements of a natural language, and an object data search
is efficiently narrowed using a simple search criterion input. A database stores
object data in association with a plurality of attribute words categorized according
to the sentence elements of a natural language. An input unit receives an input
of a search criterion in the form of a sentence of the natural language. A criterion
retrieval unit analyzes the search criterion in the form of the sentence and retrieves
one of a plurality of search words respectively corresponding to sentence element
categories of the natural language. An object retrieval unit searches the database
using each of the search words respectively associated with the sentence element
categories, retrieves the object data associated with the attribute words that
match a single search word or a plurality of search words wherein relationships
existing between at least said one of said plurality of search words corresponding
to the sentence element categories of the natural language are used with information
features associated with the attribute words to further refine searching and an
output apparatus for outputting the object data retrieved.
