Keeping Things in Context: A            Comparative Evaluation        of Focus Plus Context Screens,           Overviews, ...
Revisiting Definitions     Multi-scale Documents           Static     Visual documents that are                           ...
Revisiting Definitions (contd..)f+c                                                  z+pFocus + Context is a              ...
Legends            Breakdown or Critique            Reflection            Idea or a plausible alternative7/10/2012        ...
Research QuestionsRQ1:For users working with static documents too large and detailedto fit on their screen, controlling fo...
The Workflow                       Derive realistic tasks     Laboratory          Laboratory   Field Work                 ...
Study 1: Hypotheses• H1: Subjects would complete each task faster  with the f + c interface than with the z + p  interface...
Study 1: Method detailsParticipants– 12 Xerox PRAC employees.        No descriptive statistics of the sample? Was gender c...
Study 1: Method details (contd..)Research Design– 3 (Display techniques) X 2 (task types)                                 ...
Study 1: Results                                                                                 Graphing the meansAverage...
Study 1: Results (contd..)Source                                          Type III    df        Mean     F       Sig.     ...
Study 1: Results (contd..)Source                                          Type III   df        Mean     F       Sig.      ...
Study 1: Results (contd..)Source                                          Type III   df        Mean     F       Sig.      ...
Study 1: Results (contd..)Source          Display type       Task type   Type III   df        Mean     F       Sig.       ...
Study 1: Discussion• Switching effort was found to be the major factor to influence the  experience of an interface.• Prob...
Study 2: Hypotheses• H1: Subjects in the car task would produce lower  error rates when using f + c interface compared to ...
Study 2: Method detailsParticipants– 8 Xerox PRAC employees. (subset of previous participants)        Won’t using the same...
Study 2: Method details (contd..)Research Design– 2 (Displaytechniques) X 2 (collision types)                    f+c   o+d...
Study 2: Results                                                                              GraphingMean number of colli...
Study 2: Results (contd..)Source                                               Type III   df        Mean     F       Sig. ...
Study 2: Discussion   • Also users reported higher satisfaction (significant) with f + c     interface than o + d interfac...
Connecting the dots..• Two controlled experiments provided evidence of better  performance of f + c interfaces for navigat...
Thank you            Questions?7/10/2012                23
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Keeping things in context a comparative evaluation of focus plus context screens, overviews, and zooming

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Keeping things in context a comparative evaluation of focus plus context screens, overviews, and zooming

  1. 1. Keeping Things in Context: A Comparative Evaluation of Focus Plus Context Screens, Overviews, and ZoomingPatrick Baudisch, Nathaniel Good, Victoria Bellotti, & Pamela Schraedley Information Sciences and Technologies Lab/Computer Science Lab Xerox Palo Alto Research Center Presented By Debaleena Chattopadhyay I590, Summer 2012
  2. 2. Revisiting Definitions Multi-scale Documents Static Visual documents that are Documents that remain too large and detailed to fit unchanged unless the user on user’s computer screen modifies them. at a time. E.g. maps. E.g. maps, design diagrams. Dynamic Information streams that are changing irrespective of user involvement. E.g. games, air traffic control.7/10/2012 2
  3. 3. Revisiting Definitions (contd..)f+c z+pFocus + Context is a Zooming andvisualization technique for panning is avery large and detailed technique todocuments. display required informationThey contain wall-size low- sequentially inres displays as context terms of differentscreens and an embedded views.high-res display regioncalled focus.o+dOverview + Detail is a multi-window (usually two)visualization technique.They contain one window (overview) which alwaysdisplays the entire document, while another window(detail) shows a certain close-up. 7/10/2012 3
  4. 4. Legends Breakdown or Critique Reflection Idea or a plausible alternative7/10/2012 4
  5. 5. Research QuestionsRQ1:For users working with static documents too large and detailedto fit on their screen, controlling for the interfaces used, what isthe relationship between display techniques, type of task anduser experience (efficiency, effectiveness & satisfaction)? RQ2: For users working with dynamic information stream too complex to be perceived at a single resolution of the screen, controlling for the interfaces used, what is the relationship between display techniques, type of task and user experience (efficiency, effectiveness & satisfaction)?7/10/2012 5
  6. 6. The Workflow Derive realistic tasks Laboratory Laboratory Field Work for controlled Study on Static Study on experiments Documents Interview 14 Dynamic Views multi-scale • Board task– • 12 participants document users verifying • 8 participants • 3 display covering all five connections on a • 2 display techniques ( f techniques ( f +classes of activity. circuit board + c, o + d, z + c, o + d) • Map task – finding p) • 1 task a closest hotel on a • 2 tasks map • Driving simulation task– avoid nails on the road and falling rocks while driving. 7/10/2012 6
  7. 7. Study 1: Hypotheses• H1: Subjects would complete each task faster with the f + c interface than with the z + p interface. (one-tailed hypothesis)• H2: Subjects would complete each task faster with the f + c interface than with the o + d interface. (one-tailed hypothesis)• H3: Subjects would report higher satisfaction with the f + c interface than z + p and o + d interfaces. (one-tailed hypothesis)7/10/2012 7
  8. 8. Study 1: Method detailsParticipants– 12 Xerox PRAC employees. No descriptive statistics of the sample? Was gender controlled? How about subjects’ experience with any of the display techniques or any of the tasks?Independent Variables– Display Techniques (3 levels) and type of tasks (2levels)Dependent Variables– User Experience operationalized as time on task,accuracy in performing tasks and self reported questionnaire (adaptedfrom QUIS) No clear definition of the measures other than the questionnaire. How was accuracy in performing tasks measured? What constitutes an error?7/10/2012 8
  9. 9. Study 1: Method details (contd..)Research Design– 3 (Display techniques) X 2 (task types) Map Task Board Task z+p Two Factors f+c o+dData Analysis– Two-way repeated measures ANOVA When we carry out our experimental manipulation with same people, the within-participant variance is made up of = the effect of manipulation + individual differences in performance. We have three experimental conditions for display techniques. But since no corrected F-value is reported it is assumed that the data did not violate the assumption of sphericity (Mauchly’s test was not significant). Sphericity refers to the equality of variances of the differences between treatment levels.7/10/2012 9
  10. 10. Study 1: Results Graphing the meansAverage Task completion times in seconds 700• Effect of display type Mean time on task 600• No visible effect of 500 task type 400• No visible interaction 300 Map Task effect 200 Board Task 100 0 z+p f+c o+d Display Technique7/10/2012 10
  11. 11. Study 1: Results (contd..)Source Type III df Mean F Sig. sum of Square squares dfMDisplay Type Sphericity assumed 2 19.78 .000Error (Display Type) Sphericity assumed 22 dfRTask type Sphericity assumed 1 2.63 > .05Error (Task type) Sphericity assumed 11Display * Task Sphericity assumed 2 1.76 > .05Error (Display * Task) Sphericity assumed 22 Test of within subject effects (Plausible table) Two factors: display type and task type One effect: Completion time Display type has a significant effect on task completion times.7/10/2012 11
  12. 12. Study 1: Results (contd..)Source Type III df Mean F Sig. sum of Square squares dfMDisplay Type Sphericity assumed 2 2.23 >.05Error (Display Type) Sphericity assumed 22 dfRTask type Sphericity assumed 1 3547 .000Error (Task type) Sphericity assumed 11Display * Task Sphericity assumed 2 .60 > .05Error (Display * Task) Sphericity assumed 22 Test of within subject effects (Plausible table) Two factors: Display type and task type One effect: Task accuracy And how do we measure that? Task type has a significant effect on task7/10/2012 accuracy. 12
  13. 13. Study 1: Results (contd..)Source Type III df Mean F Sig. sum of Square squares dfMDisplay Type Sphericity assumed 2 9.30 .000Error (Display Type) Sphericity assumed 22 dfRTask type Sphericity assumed 1 0.011 >.05Error (Task type) Sphericity assumed 11Display * Task Sphericity assumed 2 0.97 > .05Error (Display * Task) Sphericity assumed 22 Test of within subject effects (Plausible table) Two factors: Display type and task type One effect: User Satisfaction Display type has a significant effect on user satisfaction.7/10/2012 13
  14. 14. Study 1: Results (contd..)Source Display type Task type Type III df Mean F Sig. sum of Square squares dfMDisplay Type o + d vs. f + c 1 19.54 .000 z + p vs. f + c 1 36.52 .000 dfRError o + d vs. f + c 11 z + p vs. f + c 11 Test of within subject contrasts (Plausible table) Two factors: display type and task type One effect: Completion time f + c yielded faster completion times than both the other display types.Planned contrasts also suggested: f + c was favored for user satisfaction over othertwo displays as well as for easier orientation to the displays. 7/10/2012 14
  15. 15. Study 1: Discussion• Switching effort was found to be the major factor to influence the experience of an interface.• Problems rose like blurriness of projection and shadow casting. • Multivariate analysis with all the dependent variables. • Control for gender. • Better operationalization of the measures. • Report Effect Size: (More so, when it is this large) F(1, dfR ) r= F(1, dfR ) + dfR • ro + d vs. f + c = 0.79 and rz + p vs. f + c = 0.88 (Very Large Effect Sizes) • Given the options, maybe a between-group design is not a good idea. With N = 12 in each of the 6 (3 X 2) conditions, we get dfR as 6 X 11 = 66. The critical F-value required for significance (p < .001) also decreases, but at the loss of the effect size.7/10/2012 15
  16. 16. Study 2: Hypotheses• H1: Subjects in the car task would produce lower error rates when using f + c interface compared to o + d interface. (one-tailed hypothesis)• H2: Subjects would ne more satisfied using the f + c interface for the car task than the o + d interface. (one-tailed hypothesis)7/10/2012 16
  17. 17. Study 2: Method detailsParticipants– 8 Xerox PRAC employees. (subset of previous participants) Won’t using the same people cater to additional change for the previous experimental manipulation? No descriptive statistics of the sample? Was gender controlled?Independent Variables– Display Techniques (2 levels) and collision type (2 levels)Dependent Variables– User Experience operationalized as accuracy in performingtasks and self reported ranking for the preferences of the interfaces. Why user efficiency was not measured? Time on task?7/10/2012 17
  18. 18. Study 2: Method details (contd..)Research Design– 2 (Displaytechniques) X 2 (collision types) f+c o+d Run-over nails Rocks hit Two Factors Data Analysis– Two-way repeated measures ANOVA7/10/2012 18
  19. 19. Study 2: Results GraphingMean number of collisions subjects caused in the car task the means 25 Number of errors• Effect of display type 20• More number of errors 15 for collision with nails, so 10 Run over nails effect of collision type.• No visible interaction 5 Rocks hit effect 0 o+d f+c Display type7/10/2012 19
  20. 20. Study 2: Results (contd..)Source Type III df Mean F Sig. sum of Square squares dfMDisplay Type Sphericity assumed 1 843.5 .000Error (Display Type) Sphericity assumed 7 dfRCollision type Sphericity assumed 1 19.71 <.01Error (Task type) Sphericity assumed 7Display * Collision Sphericity assumed 1Error (Display * Collision) Sphericity assumed 7 Test of within subject effects (Plausible table) Two factors: display type and collision type One effect: Errors Both collision type and display type has a significant effect on task accuracy.7/10/2012 20
  21. 21. Study 2: Discussion • Also users reported higher satisfaction (significant) with f + c interface than o + d interface. • Better performance in f + c may be because of the use of the peripheral vision. • Did not report effect size • Is it because o + d interface had two different screens that hindered peripheral vision? Was the overview screen in the optimal range of peripheral vision for the users? The f + c interface was overall larger in size. Was it creating an immersion effect on playing the game?7/10/2012 21
  22. 22. Connecting the dots..• Two controlled experiments provided evidence of better performance of f + c interfaces for navigating static and dynamic multi-scale documents.• Authors claim that these results suggest that f +c screens can enable individuals to carry out monitoring + interaction tasks that are now typically done by a team of at least two. Sounds a little ambitious. No baseline performance evaluation with group of users were done in the study.• No questions were asked to users to understand the effects of low-res context screen (f + c) compared to high-res overview (o + d). Did it predict the errors in f + c interfaces?7/10/2012 22
  23. 23. Thank you Questions?7/10/2012 23

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