ABSTRACT
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106
Functions: Supporting System Use . . . . . . . . . . . . . . . . 107
Taking Over Parts of Routine Tasks . . . . . . . . . . . . . . . . . 107
Adapting the Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Helping With System Use . . . . . . . . . . . . . . . . . . . . . . . . . 109
Mediating Interaction with the Real World . . . . . . . . . . . 110
Controlling a Dialogue . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Functions: Supporting Information
Acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Helping Users to Find Information . . . . . . . . . . . . . . . . . 112
Support for browsing . . . . . . . . . . . . . . . . . . . . . . . . 113
Support for query-based search or filtering . . . . . . . 114
Spontaneous Provision of Information . . . . . . . . . . . . . . 114
Recommending Products . . . . . . . . . . . . . . . . . . . . . . . . 114
Tailoring Information Presentation . . . . . . . . . . . . . . . . . 115
Supporting Collaboration . . . . . . . . . . . . . . . . . . . . . . . . 116
Supporting Learning . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
Usability Challenges . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118
Threats to Predictability and Comprehensibility . . . . . . . 119
Threats to Controllability . . . . . . . . . . . . . . . . . . . . . . . . . 119
Obtrusiveness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Threats to Privacy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Breadth of Experience . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Dealing With Trade-offs . . . . . . . . . . . . . . . . . . . . . . . . . . 120
Obtaining Information About Users . . . . . . . . . . . . . . . 121
Explicit Self-Reports and -Assessments . . . . . . . . . . . . . . 121
Self-reports about objective personal
characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Self-assessments of interests and knowledge . . . . . . 121
Self-reports on specific evaluations . . . . . . . . . . . . . 122
Responses to test items . . . . . . . . . . . . . . . . . . . . . . . 122
Nonexplicit Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
Naturally Occurring Actions . . . . . . . . . . . . . . . . . . . . . . 122
Previously Stored Information . . . . . . . . . . . . . . . . . . . . . 122
Low-Level Indices of Psychological States . . . . . . . . . . . . 123
Signals Concerning the Current Surroundings . . . . . . . . 123
Special Considerations Concerning
Empirical Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Use of Data Collected With a Nonadaptive System . . . . . 123
Early Studies of Usage Scenarios and
User Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Wizard of Oz Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Comparisons With the Work of Human Designers . . . . . . 125
Experimental Comparisons of Adaptive
and Nonadaptive Systems . . . . . . . . . . . . . . . . . . . . . . . . 125
Taking Into Account Individual Differences . . . . . . . . . . 126
Checking Usability Under Realistic Conditions . . . . . . . . 126
The Future of User-Adaptive Systems . . . . . . . . . . . . . 126
Growing Need for User-Adaptivity . . . . . . . . . . . . . . . . . 126
Diversity of users and contexts of use . . . . . . . . . . . 126
Number and complexity of interactive systems . . . . 126
Scope of information to be dealt with . . . . . . . . . . . 126
Increasing Feasibility of Successful Adaptation . . . . . . . . 127
Ways of acquiring information about users . . . . . . . 127
Advances in techniques for learning,
inference, and decision . . . . . . . . . . . . . . . . . . . . . . . 127
Attention to empirical methods . . . . . . . . . . . . . . . . 127
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
This chapter covers a broad range of interactive systems. They all have one idea in common: It can be worthwhile for a system to learn something about each individual user and adapt its behavior to them in some nontrivial way.
