The paper describes how slight changes to a free‐text retrieval system (DECO) enable two methods of searching (free‐text and hierarchical) to be offered in one system (VIEWDECO). Users are thus free to choose either method, without the need to switch between different databases. Apart from introducing menus, which are an integral part of a viewdata (hierarchical) system, the technique has also been used to incorporate help messages and other instructional aids. A third method of searching, the ‘Electronic Book’, is also described. Providing three methods of searching in one retrieval system caters for users with a much wider range of skills, and presents an opportunity for a gradual, self‐paced transition to free‐text searching. The technique involves relatively small changes, and should be applicable to many other inverted file, free‐text retrieval systems.
