The importance of iterative prrocedures in the design of location maps for the built environment

This paper reports the development of a hand-held sketch map intended to help people find clinics and other facilities in a hospital Outpatients Department. The map illustrated the whereabouts of more than 50 locations which were divided between two floors, Considerable thought and consultation went into the design of the map. Empirical evaluation was carried out by asking members of the public to use the map to find specific locations in the building. This showed that some of the information on the map was not understood at all, some was misinterpreted and some was ignored. Analysis of people's difficulties suggested that over 20 revisions were needed and that these fell into six broad categories, which included readers' presuppositions about the labelling of the built environment, their interpretation of iconic information on the map, and their use of way-finding information both on and off the map. This led to a revised map, which further testing showed overcame the previous problems. However, subsequent requests for extra details on the map showed that the design solutions did not necessarily remain adequate when new information was introduced. Numerous subtle factors could cause ambiguities for readers and undermine the map's effectiveness. Although the error analysis pointed to general design principles for this kind of location diagram, these principles were goals rather than procedures which could guarantee the success of such maps. Empirical evaluation provides the only certain way of knowing that a location map is adequate for its purpose,