1. Is Context-Aware Computing Taking Control Away from the User? Three Levels of Interactivity Examined Louise Barkhuus and Anind Dey The IT University of Copenhagen, Intel Research Berkeley Proceedings of UbiComp, 2003 2008. 11. 19. Summarized by Jaehui Park, IDS Lab., Seoul National University Presented by Jaehui Park, IDS Lab., Seoul National University

2. Copyright  2008 by CEBT Contents  Introduction  Three Levels of Interactivity Personalization Active Context Awareness Passive Context Awareness  Case Study Perception of Control Preference for Active and Passive Context-Awareness  Discussion & Conclusion 2

3. Copyright  2008 by CEBT Introduction  User perception of context-aware interaction  The level of interactivity Varies between many applications – Letting the user manually define parameters on how an application behave – Automatically providing the user with services and information  A study Examine users’ sense of control and their preference to interactivity level – Mobile phone 3

4. Copyright  2008 by CEBT Introduction  Three levels of interactivity Personalization – Applications let user specify his own settings how the application should behave in a given situation Passive context-awareness – Updated context or sensor information presents to the user – Let user decide how to change the application behavior Active context-awareness – Autonomously change the application behavior according to the sensed information  Case study Analyzing users’ attitudes toward each of the levels of interactivity – Guide the development of future context-aware service in having an appropriate level of interactivity 4 loss of control Higher interaction cost

5. Copyright  2008 by CEBT Three Levels of Interactivity  Personalization Customization or tailoring Diversity and dynamics of applications call for an increased level of tailoring in software Emphasis on customized functionality will add to the user experience and smoothness of interaction – Ex) setting preference for background picture and ringing profile in mobile phone – Interesting thing Even though many application offer personal tailoring, the majority of users use the default setting or change small subset 5

6. Copyright  2008 by CEBT Three Levels of Interactivity  Active Context-Awareness (proactive) Application that, on the basis of sensor data, change their content autonomously – Ex) the mobile phone that changes its time automatically when the phone enters a new time zone  Passive context-Awareness (push, interactive) Application that merely present the updated context to the user and let the user specify how the application should change, if at all. – Ex) the mobile phone prompts the user with information about the time zone change and lets the user choose whether the time should be updated or not.  There are many of definitions about the levels of interactivity 6

7. Copyright  2008 by CEBT Case Study  Comparing users’ responses toward application Representing three levels of interactivity  Research Method Each participant is assigned to a group Six different services were proposed Five day fill-in diary – How many times they would have used the services – What degree they thought the services would have been useful Evaluated on a scale 1-5 Interview (with 6 of participants) – elaborating their reactions and overall perception of context-awareness  Participants 23 participants – Using mobile phone frequently – age 19~35, phone ownership ½~6 – Randomly assigned to the groups 7 N=23PersonalizationPassive Context Awareness Active Context- Awareness N887 Avg. age23.722.925 Avg. mobile phone ownership 2.2 years2.6 years2.7 years Avg. user level (1~6) 3.13.83.4

8. Copyright  2008 by CEBT ServicePersonalizationPassive Context-AwarenessActive Context-Awareness A: Private ringing profiles Different ringing profiles that are set manually The phone prompts the user to adjust the profile when sensing it is in a meeting or class The phone automatically changes profile when sensing the user is at a meeting or in class B: Public ringing profiles Different ringing profiles that are set manually The phone prompts the user to adjust the profile when sensing it is in a movie theater or at a restaurant The phone automatically changes profile when sensing the user is at a movie theater or at a restaurant C: Lunch service Manual search for appropriate lunch place Single alert around noon for lunch place according to users’ preferences Alerts the user when passing by a lunch place of relevance and suggests places at noon D: Class slides Manual search to see if class slides are available online If signed up, the phone alerts user of available slides for class Automatic alert every time the teacher updates class slide website E: Location tracking Manually location tracking of predefined friends Locations tracking of friends and setting to alert when they are within a certain range Location detection of friends that alerts when they are within 300 feet of user F: Activity tracking Display of potential call- receiver’s social situation (e.g. meeting, home, out) In a new context, the phone prompts the user to display the user’s situation to possible callers Automatic switch to display of social situation when entering a new context 8

9. Copyright  2008 by CEBT Perception of Control  Hypothesis People felt less in control when using context-awareness services, than when personalizing applications  proved to be true asking directly, analyzing interviews Each of the services were evaluated according to the perception at the end of each day  The more autonomous the service is, the less users felt in control Correlation between the level of interactivity and the participants perception of control = -0.26 When considering two level of context-awareness as one = -0.31  The personalization group felt more in control than both other groups A, B, D But the opposite was true for E – Controversial nature of tracking the user’s location It does not matter if display of location information can be controlled  Last two services didn’t show difference in perception of control  Most of the participants feel they have control of their mobile phone with their currently available personalization-based applications 9

10. Copyright  2008 by CEBT Preference for Active and Passive Context-Awareness  Participants preferred active context-awareness and passive context- awareness over personalization  Measuring preference How many times the participants would have used it on a specific day Participants rate the service for usefulness  They found (unexpected) correlation B : 0.29, E: 0.31 (significant at.025 level) – Higher level of interaction resulted in higher level of preference Opposite (F: -0.43) – The most popular version of this services was the personalization oriented and the least preferred was the active context-aware one  Preference for interaction level vary across service (not across individuals) A,B,E : very popular, D,F : fairly irrelevant, D : too intrusive 10

11. Copyright  2008 by CEBT Discussion  Owning a mobile phone in itself constitutes some lack of control Since the user can be reached anywhere at anytime Having less control is the cost of becoming more interactive  Participants might become frustrated by their perceived lack of control and eventually turn the service off  Imaginary approaches are not always sufficient to tell if users would actually behave as they self-reported 11

12. Copyright  2008 by CEBT Reviews  Pros. Interesting topic  Cons. Confusing terminologies Unreliable case study No analysis about the experimental results 12

13. Copyright  2008 by CEBT Conclusion  We have examined people’s sense of control and preference for three levels of interactivity within mobile computing  Participants feel a lack of control when using the more autonomous interactivity approaches  Participants prefer active and passive context-awareness features over personalization in most cases  Users are willing to accept a large degree of autonomy from application as long as the application’s usefulness is greater than the cost of limited control 13