Codifying Distributed Cognition: A Case Study of Emergency Medical Dispatch

..............................................................................................................................................3 TABLE OF CONTENTS..........................................................................................................................4 TABLE OF TABLES................................................................................................................................5 TABLE OF FIGURES..............................................................................................................................5 GENERAL INTRODUCTION ................................................................................................................6 INTRODUCTION TO EMERGENCY MEDICAL DISPATCH (EMD) ............................................7 LONDON AMBULANCE SERVICE (LAS) CENTRAL AMBULANCE CONTROL ROOM (CAC).......................7 An Overview ......................................................................................................................................7 A Brief History...................................................................................................................................7 THEORETICAL APPROACHES AND CHALLENGES IN EMD........................................................................8 INTRODUCTION TO DISTRIBUTED COGNITION .......................................................................10 BACKGROUND.......................................................................................................................................10 The Heritage of a Disembodied Cognitive Science for HCI ............................................................10 Criticisms of Disembodied Cognitive Science .................................................................................11 A Conception of the Extended Mind ................................................................................................13 DESCRIBING THE DISTRIBUTED COGNITION PERSPECTIVE ....................................................................16 Core Tenets and Concepts ...............................................................................................................16 THE DEVELOPMENT OF DISTRIBUTED COGNITION IN HCI.....................................................................22 METHOD ................................................................................................................................................25 MATERIALS AND PRACTICAL CONSTRAINTS .........................................................................................25 LITERARY SUPPORT ..............................................................................................................................25 STAGES OF ANALYSIS UNDERTAKEN ....................................................................................................28 ANALYSIS OF LONDON AMBULANCE SERVICE (LAS) CENTRAL AMBULANCE CONTROL ROOM (CAC) ....................................................................................................................30 OVERVIEW OF THE ANALYSIS ...............................................................................................................30 INFORMATION FLOW MODEL ................................................................................................................31 Overview: High Level Input-Output Diagram.................................................................................31 Flow of Information: Looking at communication channels.............................................................32 Flow of Information: Overview of key flow properties....................................................................43 PHYSICAL MODEL .................................................................................................................................48 Sector Desk Level ............................................................................................................................49 Room Level ......................................................................................................................................52 ARTEFACT MODEL ................................................................................................................................55 Incident Card and Tray System .......................................................................................................56 Screen Representations....................................................................................................................65 Call Taker Status Board ..................................................................................................................70 SUMMARY OF RESULTS .........................................................................................................................71 THE CODIFIED DISTRIBUTED COGNITION (DC) METHOD....................................................72 OVERVIEW ............................................................................................................................................72 DATA GATHERING ................................................................................................................................72 BUILDING A DESCRIPTION: THE MODELS..............................................................................................74 The Hierarchical Levels within the Models .....................................................................................74 The Models ......................................................................................................................................74 CONCLUSION.........................................................................................................................................78 DISTRIBUTED COGNITION DESIGN SCENARIOS ......................................................................79 GENERAL APPROACH ............................................................................................................................79 INTRODUCTION TO ALTERNATIVE LAS CAC DESIGNS .........................................................................80 1. Retrospective Design ...................................................................................................................80 2. Progressive Design......................................................................................................................83