1. A method of operation in a search engine for a multiple inheritance concept hierarchy comprising the steps of: providing computer screen displays of two search classes including at least one screen display of a class covering concept terms arranged in tree view of the multiple inheritance concept hierarchy and at least one other screen display of a class covering terms for properties attributable to one or more of the concepts of the hierarchy for the selection, by a user, of one of the screen display of the classes; establishing a third computer screen display containing a dictionary of the terms used in the hierarchy that fall within a selected one of the two classes and creating a visualization of terms from the selected class for the choosing of search terms from the dictionary; and associating in the third computer screen the terms of the selected class each with terms from a nonselected class so that the search term can be used for selecting of one of the associated terms as a further search term by the user.