This volume represents a tribute by friends, family and colleagues to Hugh Sackett, a British archaeologist who led important excavations at Knossos, Palaikastro and Lefkandi in Greece. Organised in two parts, Reminiscences and Archaeological Contributions, the texts speak both to Hugh's dual life as archaeologist and teacher, and his important contributions to Aegean and Greek prehistory. These varied papers, many richly illustrated, refl ect on his impact in the fi eld or discuss specifi c details of the sites he worked on. Other texts treat more general aspects of Greek prehistory. Many of the contributions discuss the site of Palaikastro where Hugh worked fi rst in the early 1960s and then again from 1983 onwards.
A TASK MODEL-BASED APPROACH FOR THE DESIGN AND EVALUATION OF INNOVATIVE USER INTERFACES ....................... 3
CHAPTER 1- INTRODUCTION.................................................................. 5
1.1 OBJECTIVES ............................................................................................. 7
1.2 OUTLINE .................................................................................................. 8
CHAPTER 2 - TASK MODEL -RELATED CONCEPTS ....................... 11
2.1 MODEL-BASED APPROACHES ................................................................ 11
2.2 NORMAN'S ACTION CYCLE MODEL....................................................... 14
2.3 TASK ANALYSIS METHODS.................................................................... 15
2.3.1 Task Analysis ................................................................................. 15
2.3.2 Groupware Task Analysis (GTA)................................................... 19
2.4 TASK MODELLING ................................................................................. 20
2.4.1 Methode Analytique de Description des Taches (MAD)................ 21
2.4.2 Goals, Operators, Methods, and Selection Rules (GOMS) .......... 23
2.4.3 User Action Notation (UAN).......................................................... 24
2.4.4 Activity Diagrams .......................................................................... 25
2.4.5 Conclusions.................................................................................... 26
CHAPTER 3 - THE CONCURTASKTREES NOTATION AND THE RELATED ENVIRONMENT ..................................................................... 29
3.1 INTRODUCTION ...................................................................................... 29
3.2 THE CONCURTASKTREES NOTATION (CTT).......................................... 31
3.2.1 Task Properties .............................................................................. 32
3.2.2 Operators ....................................................................................... 35
3.3 CTT ENVIRONMENT (CTTE)................................................................. 37
CHAPTER 4 - A TASK MODEL-BASED APPROACH FOR THE DESIGN, VERIFICATION AND EVALUATION OF INTERACTIVE SYSTEMS............ 41
4.1 INTRODUCTION ...................................................................................... 41
4.2 THE MEFISTO APPROACH ...................................................................... 42
4.2.1 The Process Cycle.......................................................................... 43
4.2.2 The Design Cycle ........................................................................... 45
4.2.3 The Abstraction Cycle.................................................................... 46
4.3 THE PROPOSED APPROACH .................................................................... 49
CHAPTER 5 - HOW TO DESIGN INTERACTIVE SYSTEMS FROM TASK MODELS ........................................................................................... 55
5.1 INTRODUCTION ...................................................................................... 55
5.2 RELATED WORK .................................................................................... 57
5.3 SPECIFYING ABSTRACT DESCRIPTIONS OF USER INTERFACES................ 61
5.4 THE PROPOSED APPROACH .................................................................... 63
5.5 FROM TASK MODELS TO ABSTRACT USER INTERFACES ........................ 65
5.5.1 Identifying PTS and Transitions .................................................... 65
5.5.2 Applying Heuristics........................................................................ 67
5.5.3 Mapping PTS-Based Specifications onto Interactor-Based Descriptions ............................................................................................ 69
5.6 FROM AN ABSTRACT USER INTERFACE TO ITS IMPLEMENTATION.......... 75
5.7 A SIMPLE EXAMPLE............................................................................... 76
CHAPTER 6 - USING TASK MODELS TO VERIFY PROPERTIES OF AN INTERACTIVE SYSTEM.................................................................... 81
6.1 INTRODUCTION ...................................................................................... 81
6.2 RELATED WORK ................................................................................... 83
6.3 THE APPROACH...................................................................................... 85
6.4 FROM CTT TO LOTOS.......................................................................... 90
6.4.1 Single-User Task Models ............................................................... 92
6.4.2 Cooperative Task Models .............................................................. 96
6.5 PROPERTY FORMALISATION AND VERIFICATION.................................... 98
6.5.1 The Approach................................................................................. 98
6.5.2 Sample Properties.......................................................................... 99
6.6 INTEGRATING CTTE WITH A MODEL-CHECKING TOOL....................... 102
6.7 AN EXAMPLE OF APPLICATION ............................................................ 107
CHAPTER 7 - INTEGRATING TASK MODELS AND SYSTEM MODELS..................................................................................................... 111
7.1 INTRODUCTION .................................................................................... 111
7.2 SYSTEM MODELLING ........................................................................... 113
7.2.1 Petri Nets (PN)............................................................................. 113
7.2.2 Interactive Cooperative Objects (ICO)........................................ 115
7.2.3 PetShop Environment................................................................... 117
7.3 THE INTEGRATION FRAMEWORK ......................................................... 120
7.3.1 CTT Environment......................................................................... 125
7.3.2 ICO Environment......................................................................... 125
7.3.3 The Correspondence Editor......................................................... 126
7.3.4 Execution: the Scenario Player ................................................... 127
CHAPTER 8 - TASK MODEL–BASED EVALUATION OF INTERACTIVE SYSTEMS....................................................................... 129
8.1 INTRODUCTION .................................................................................... 129
8.2 RELATED WORK .................................................................................. 130
8.3 THE METHOD....................................................................................... 134
8.3.1 Organisation of the Evaluation.................................................... 137
8.4 AN EXAMPLE OF APPLICATION ........................................................... 139
8.4.1 Evaluating a Low-Level Task....................................................... 139
8.4.2 Evaluating a High-Level Task ..................................................... 141
CHAPTER 9 - A CASE STUDY................................................................ 143
9.1 INTRODUCTION .................................................................................... 143
9.2 THE ATC DOMAIN .............................................................................. 144
9.2.1 The En-route Phase...................................................................... 146
9.2.2 The Aerodrome Phase.................................................................. 148
9.3 APPLYING THE APPROACH TO THE CASE STUDY.................................. 151
9.3.1 Designing ATC User Interfaces................................................... 151
9.3.2 Verifying Properties..................................................................... 157
9.3.3 Integrating Task Models and System Models .............................. 163
9.3.4 Deviation-Based Evaluation ........................................................ 179
CHAPTER 10 - CONCLUSIONS AND FUTURE PERSPECTIVES... 187
REFERENCES............................................................................................ 191
TABLE OF CONTENTS ........................................................................... 207