Depending on our life being matured, our ability to create concept is indispensable. Based on our concept creation model focusing on ambiguous items that make to wave one's decision, we developed a web-based creativity support system that is expected to make players enjoy categorization of words in analogical reasoning so as to make batch of words to discover new concepts. 20 junior high school students participated in an experiment, where concept creation is expected to be induced by an ambiguous interpretation of presented information under constrained rule. As a result, we find some evidences that an existence of ambiguous items corresponds to diversification of thought process either as insight or try & errors in categorization of words. We also show that the reconstruction of groups for including ambiguous items into some groups accelerates the creation of new concepts for individual's better interpretation.