1. If Not Now, When? The Effects of Interruption at Different Moments Within Task Execution Piotr D. Adamczyk, Brian P. Bailey Graduate School of Library and Information Science and Department of Computer Science University of Illinois at Urbana-Champaign Champaign CHI 2004

2. Outline INTRODUCTION RELATED WORK METHODOLOGY USER STUDY RESULTS DISCUSSION CONCLUSION

3. INTRODUCTION Proactive applications (email agents, instant messaging) do not consider the impact an interruption has on a user. Poorly timed interruptions can adversely affect task performance and emotional state.

4. RELATED WORK Visual and Multimodal Strategies for Interruption Temporal Strategies for Interruption Event Perception

5. METHODOLOGY Task Modeling – prediction regarding moments for interruption.

6. Task Modeling

9. USER STUDY Experimental Design Subjects Tasks Interruptions Procedure Measurements

10. Experimental Design 3 task type: – Editing, Media, Searching. 4 interruption trigger: – presumed best, presumed worst, random, no.

11. Subjects Sixteen subjects – 13 male and 3 female.

12. Tasks The first was a document-editing task.

13. Tasks The second task class consisted of four short documentary or news media clips.

14. Tasks The final task class was a web-searching task.

15. Interruptions immediately and accurately, without moving the interrupting window.

16. Procedure First sent a sample instance of the task type. Second answer any questions that might arise. Finally, subjects were told to take the whole task execution.

17. Measurements Time on Task (TOT) was the total trial time minus the Time on Interruption (TOI) an approximate value for Resumption Lag.

18. RESULTS TOT, TOI, Resumption Lag Annoyance, Frustration, Time Pressure Mental Demand, Mental Effort Respect

19. TOT, TOI, Resumption Lag

20. Annoyance, Frustration, Time Pressure

21. Mental Demand, Mental Effort

22. Respect

23. DISCUSSION Our results show significant impacts along a variety of scales.

24. CONCLUSION An attention manager attempts to identify opportune moments in a user’s task sequence for an interruption to occur. User wouldn’t be required to rehearse, as the points at which the interruptions would occur would be easier to recall.