A Diary Study of Task Switching and Interruptions

1. A Diary Study of Task Switching and Interruptions Toward Understanding & Supporting Multitasking Mary Czerwinski Eric Horvitz Susan Wilhite Microsoft Research

2. Motivation and Goals • Hypothesis: Current MS software does not support multitasking well • How bad/universal is the problem? • Seek SW design ideas… • Research shows users developing workaround strategies • Interruptions research shows harmful effects of incoming notifications on current task • Memory for To Do’s notoriously poor, undersupported CHI 2004

3. Approach • Earlier Work: • Characterize memory for important computing events • Memory augmentation systems—will they work? • Current Study: • Capture nature of interruptions in typical user’s day • Characterize frequency of task switch/returns • Gather data on what constitutes a “task” • Long-term Goal: Design new UI’s for semi-automated, efficient access to prior task contexts CHI 2004

4. Memory Research •  Retrospective Memory • Memory for past events—organized into episodes • Strong Cues: people, place, key events, (time) • Not much computer support traditionally (calendar) • Prospective Memory  • Memory for future actions or events • Retrieval cues often internally generated (must remember to remember), but people, places prompt too • Relies some on retrospective memory for cuing event • More computer support via reminders • Users still use all kinds of alternative methods to remember stuff CHI 2004

5. Previous Work • Prospective memory failures are a serious problem for information workers (Eldridge, Sellen & Bekerian, 1992; Terry, 1988) • Users come up with unique ways of remembering (Gwizdka, 2000; Jones, Bruce & Dumais, 2001) • Users’ memories for computing events erode quickly (Czerwinski & Horvitz, 2002) • Still little is known about the mechanisms for bringing intentions to mind (Sellen et al., 1992) • Or how technology could be used to reduce forgetting after a task switch or interruption CHI 2004

6. Memory “Prostheses” • Video diaries (Lamming et al., 1994) • Useful, but require real time for review • Personal stills (Czerwinski et al., 2002) work well • Still require efficient browsing mechanism • Hard to automatically detect key stills • Action history + explanations for programming error recovery (Renaud, 2000) • Forget Me Not (Lamming and Flyn, 1994)—first wearable • Continuously logged user’s physical location, workstation activities, file exchange and printing, phone calls, email, and other users present • Filter based on person, place, object, time, etc. CHI 2004

7. Memory Prostheses (Continued) • Remembrance Agent (Rhodes & Starner, 1996)—automatic text retrieval based on user’s current location • Time Machine Computing (Rekimoto, 1999)—access to desktop contents in past or future • Cyberminder (Dey & Abowd, 2000) • Memory Glasses (Pentland et al., 2000) • Lifestreams (Gelernter et al. 96), etc. • These techniques seem useful—would they help the average information worker? CHI 2004

8. Diary Study • What are the important issues related to novel sw design for multitasking? • Does it seem memory prosthesis would help? • Wanted to characterize task switching: • Over multiple days • In situ • Users’ own descriptions of how they multitask CHI 2004

9. Participants • 11 Participants recruited from a wide variety of work backgrounds (1 dropped) • Professor, CAD programmer, web page designer, boat salesman, graphics artist, developer, stock broker, real estate agent, etc. • All participants were experienced computer users, as per standardized screener • All reported they were responsible for multiple projects at once, and proud of it • Good mix of deadline-driven v. self-directed CHI 2004

10. Methods • All users completed a baseline survey once recruited • An excel spreadsheet was used as a diary “template” to be filled out each day • Diaries emailed back to me each evening • Participants instructed to write down every “task switch” • how hard to switch, # of docs required, # of interrupts experienced, task time, anything forgotten, notes, etc. CHI 2004

11. Partial diary for MS (6 hours) CHI 2004

12. Task Descriptions for BH (6 hours) • Daily Schedule Preparation • Synch PocketPC • Check Internet Email • Check and respond to email • Matlab coding • Create Charts for Meeting • Edit Word documents for meeting • Meeting • Matlab coding CHI 2004

13. Overall Diary Results • Threw out 1 participant (little task switching) • Diaries were coded for Task Type, Switch Type • Codes were validated between two researchers @ ~ 97% agreement • In addition, task times, difficulty ratings, # of interruptions and documents analyzed • Analyzed difference between “task returns” and other task types • Used linear regression to identify key variables CHI 2004

14. Task Breakdown Indicative of Difficulty Tracking Tasks “Returned to” Tasks from this group CHI 2004

15. Number of Documents per Task (Conservative) CHI 2004

16. Frequency of Interrupts (Conservative) CHI 2004

17. Task Priority CHI 2004

18. Task Times CHI 2004

19. Frequency of Task Shift Initiators CHI 2004

20. Overall Difficulty Switching Tasks CHI 2004

21. Difficulty Switching by Type CHI 2004

22. Difficulty Returning to Task by Elapsed Time CHI 2004

23. Task Length by Type CHI 2004

24. Document Requirements by Task Type CHI 2004

25. Interruptions by Task Type CHI 2004

26. Discussion of Findings • During a given week, KWs task shift an awful lot (avg. 50 task shifts weekly) • Long-term projects are more complex shifts • Lengthier (11.25% of the week), more documents, interrupts, “returns” • Rated significantly harder to return to • Negative influence of interrupts on multitask performance and memory well known • Passage of time also takes its toll • What designs will help? CHI 2004

27. General Design Ideas from Participants • Smarter, adjustable To Do list tracking & alarming • In the projects versus just in Calendar • Consider sticky notes for partial / future tasks • Auto-categorization of email and files • Better reminders for things forgotten • Track events we know about and visualize them, or rely on user manual tagging • Better user adaptivity • e.g., knowing what kinds of paste operations a user typically performs and automating them CHI 2004

28. Focus on Returned to Tasks • Elapsed time spanned hours to days • Maintaining desktop state isn’t always the answer • Often, users said they were waiting on info from other people or places (web, server)—prospective reminders needed here • Info came in via phone, email, web, or personal contacts (better app integration needed here) • But reminding about task context and info assembly / layout was a key problem identified CHI 2004

29. Color Plate 1. Scalable Fabric showing the representation of three tasks as clusters of windows, and a single window being dragged from the focus area into the periphery. Tools for Task Management • GroupBar joins related items in the taskbar, remembers spatial layouts of tasks (Smith et al., 2003) • Desktop “snapshots” • Can “rehydrate” tasks with the press of a button • Scalable Fabric and VibeLog to be presented at AVI 2004 • Visualizations of task activity a continued focus • Future designs will merge all apps, across devices CHI 2004

30. Timelines: • Task Timeline Visualizations Should Help Information Workers • Rekimoto’s Time Machine Computing • Gelertner’s Lifestreams, • On the right track! CHI 2004

31. Thanks for Your Attention • Contact/Further Info: • marycz@microsoft.com • http://research.microsoft.com/research/vibe CHI 2004

32. Many Assume Disruptions are Unavoidable… • Recent focus on memory augmentation systems • Reminder systems using automatically recognized indices of computing events • But need to know what key events users remember/forget and why • What external cues can be useful to them (Sellen et al., ‘92) to aid retrieval? • When is such a system useful? CHI 2004