When implementing an IR system that can support comprehensive searches from a wide variety of documents, it is crucial to have a mechanism for selecting appropriate query formulations. For this purpose, many IR systems can modify query terms by estimating the user?s information need. However, because modified query terms are usually represented in a complicated form, it is difficult to judge how appropriate they are. In this research, we assume all relevant documents should contain words that correspond to concepts that the user would like to retrieve. Therefore, a Boolean query formula is one good way to represent a user?s information need with high readability. To find the required concepts in a relevant document set, we have previously proposed a new IR system that calculates appropriate generalized concepts to represent the user?s need. In this study, we implement a user interface that supports reformulation of IR queries by using abstract concepts.