Cartographic and Cognitive Perspectives on Ambulance Dispatch Displays

Abstract

This chapter deconstructs the results of cognitive and Human–Computer Interaction (HCI) studies on the ambulance dispatcher displays in two emergency medical dispatch centres in New Zealand from a cartographic perspective. This is based on the recognition that any spatial component in such displays are not necessarily being designed with any geographic or cartographic input in the design process. First, two reported studies on the Southern Region Communication Centre at Dunedin were reinterpreted geographically. In rearranging the dispatcher display so that the listed ambulance stations now assumed their approximate geographical locations (a change that resulted in a significant improvement), with linking lines (not significant), the cognitive principle originally tested, the Proximity Compatibility Principle (PCP), is intuitively geographical as well as using topological representation for effective display. Secondly, the results of a study on the Northern Region Communication Centre (presiding over a more complex domain), specifically the city of Auckland, reflected the use of PCP in the context of a novel multi-layer display (MLD). This display has an opaque back display layer (used in this case to represent background elements) and a transparent front display layer (used to “promote” elements relating to matters of urgency to the foreground). Whether considered as one layer or two layers, the map-like display that the northern dispatchers use was a clear case for several cartographic symbology, generalisation and transparency layering (afforded by the MLD) initiatives. The strong parallels between display design principles and cartographic theory must be exploited in future display design processes, not just for displays serving emergency time-critical situations but the ubiquitous displays (i.e. mobile smartphones) that millions of people use on a daily basis.