Are concepts useful for organizing search results?

This paper reports an explorative study on organizing search results by concepts that are selected titles of Wiki pages. Because of limited display areas and for ease of navigation, two novel algorithms identify at most three general concepts, and at most five of their specific concepts for display. Our evaluation shows that the retrieval effectiveness improvement is significant at 90% confidence level using the paired student's t-test, albeit our users have no access to document titles nor to the content.