Cognitive modeling of voluntary task switching in discretionary multitasking

다국어 초록 (Multilingual Abstract)

This paper explores cognitive processes, including the development of an adaptive control of thought-rational (ACT-R) model to represent an integrated account of voluntary task switching in discretionary multitasking. Discretionary multitasking has emerged as a prevalent and important domain in research on human-computer interaction. Studies on modeling based on cognitive architectures such as ACT-R to gain insight into and predict human behavior in multitasking are critically important. However, studies on ACT-R modeling have mainly focused on concurrent and sequential multitasking, including scheduled task switching. Therefore, in this study, an ACT-R cognitive model of voluntary task switching in discretionary multitasking was developed to provide an integrated account of when and how humans decide on switching tasks. Our model contains a symbolic structure and subsymbolic equations that represent the cognitive process of task switching as self-interruption by the imposed demands and a decision to switch. In our model, self-interruptions by negative emotions emerge from imbalances between the difficulty of the ongoing task and the level of ability, and our model includes the rational decision to switch based on the ACT-R utility system. To validate our model, it was applied to an illustrative dual-task, including a memory game and a subitizing task, and the results were compared with human data. The results demonstrate that our model can provide a relatively accurate representation, in terms of task-switching percent just after the subtask, the number of task-switching during the subtask, and performance time depending on the task difficulty level; it exhibits enhanced performance in predicting human behavior in multitasking and demonstrates how ACT-R facilitates accounts of voluntary task switching. The proposed model can be used as a practical tool for evaluating aid systems in multitasking environments.

목차 (Table of Contents)

• ABSTRACT ·················································· ⅰ
• LIST OF FIGURES ·················································· ⅵ
• LIST OF TABLES ·················································· ⅶi
• 1. INTRODUCTION ·················································· 1
• 1.1 Background ·················································· 1
• 1.2 Problem Statement ·················································· 5
• 1.3 Research Objective ·················································· 8
• 1.4 Organization of the Thesis ·················································· 9
• 2. LITERATURE REVIEW ········································ 11
• 2.1 Theoretical Accounts for Task Switching ······························ 11
• 2.1.1 The availability of cognitive resources······························ 11
• 2.1.2 Negative emotions ·················································· 12
• 2.1.3 Time on task ·················································· 14
• 2.1.4 STOM model ·················································· 15
• 2.1.5 Summary ·················································· 17
• 2.3 ACT-R Cognitive Architecture ········································ 19
• 3. ACT-R MODELING OF VOLUNTARY TASK SWITCHING········································ 23
• 3.1 Assumptions ···························································· 23
• 3.2 Symbolic Structure of the Proposed Model ······························ 24
• 3.2.1 The first stage: interrupt-task ········································ 24
• 3.2.2 The second stage: decision-to-switching ··························· 28
• 3.2.3 The third stage: do-(not)-task-switching ··························· 29
• 3.3 Sub-symbolic Structure of the Proposed Model·························· 31
• 3.3.1 Level of imbalance parameter ········································ 31
• 3.3.2 Rule utility parameter ········································ 34
• 3.4 ACT-R Model Discussion ········································ 36
• 4. MODEL VALIDATION ········································ 39
• 4.1 Design ···························································· 39
• 4.2 Subjects and Apparatus ·················································· 45
• 4.3 Experimental Procedures ·················································· 46
• 4.4 ACT-R Model ···························································· 48
• 4.4.1 Procedural rules ·················································· 48
• 4.4.2 Primary task ·················································· 49
• 4.4.3 Task-switching and secondary task ······························ 55
• 4.5 Results and Discussion ·················································· 59
• 5. GENERAL DISCUSSION ········································ 67
• 5.1 Comparison with the threaded cognition model·························· 70
• 5.2 Practical and Theoretical Implications ······························ 74
• 5.3 Conclusion ···························································· 77
• References ·················································· 78
• Appendix. ACT-R model ·················································· 90