The data standards evolved by IRGMA (Information Retrieval Group of the Museums Association) and later by MDA (the Museum Documentation Association) enabled the production of a recording form, suitable both for a manual record card and for computer input. By using this MD System a manual catalogue can be translated into a computerized one, without re-cataloguing. MDA is finalizing a package of programs (known as GOS) to generate a variety of indexes and lists from the large hierarchical structure of the MDS, and pilot tests are being run on data from several British museums. The economics of publishing bulky print-out indexes and catalogues suggest that microfiches may have to be employed by museums for this purpose. Trials are under way for type-setting direct from the computer magnetic tape, which is another way to reduce unit costs. The interactive use of computer terminals for information retrieval is not currently justifiable in terms of economics, or demand.