1. L ARGE D ISPLAYS I MPROVE 2 D AND 3 D N AVIGATION By JOHN BELL and TOM PETERKA University of Illinois at Chicago CS 522 Human Computer Interaction Professor Moher, Spring 2005 10 February 2005

2. John Bell and Tom Peterka10 Feb 2005CS 522 This presentation is based on two major papers: Desney Tan School of CS, Carnegie Mellon Peter ScupelliDarren GergleRandy Pausch “With Similar Visual Angles, Larger Displays Improve Spatial Performance”, CHI 03 “Physically Large Displays Improve Path Integration in 3D Virtual Navigation Tasks”, CHI 04

3. John Bell and Tom Peterka10 Feb 2005CS 522 The authors make 3 key points: Large displays work better for 2D tasks. Large displays work better for 3D tasks. The observed effects are cognitive, not locomotive. But first, some background on large displays...

4. John Bell and Tom Peterka10 Feb 2005CS 522 Tan et al. provide location and place to aid human memory in the Infocockpit.

5. John Bell and Tom Peterka10 Feb 2005CS 522 MacIntyre et al. support multitasking and background awareness using interactive peripheral displays.

6. John Bell and Tom Peterka10 Feb 2005CS 522 Baudisch et al. compare focus + context vs. overviews vs. zooming and panning.

7. John Bell and Tom Peterka10 Feb 2005CS 522 Robertson et al. manage windows in 3D space in The Task Gallery.

8. John Bell and Tom Peterka10 Feb 2005CS 522 Key Concepts and Terminology Wide field of view ( FOV ) increases presence. Do large displays provide similar benefits? Egocentric perspective perceives the user to be moving in a stationary universe. Exocentric perspective perceives the universe to be moving around a stationary user. Path integration is a wayfinding method that requires the user to “integrate” their motion, as opposed to piloting by navigational landmarks. Active navigation has the user controlling the joystick; Passive allows him / her to ride along.

9. John Bell and Tom Peterka10 Feb 2005CS 522 Large displays are better in 2D. Tan et al., “With similar visual angles, larger displays improve spatial performance,” CHI 03. Fig. 1

10. John Bell and Tom Peterka10 Feb 2005CS 522 The experiment hardware consisted of large and small displays at same FOV; the input device was a USB keypad. 24 college students participated, 12 male. A primary study and follow up study were conducted. Fig. 2

11. John Bell and Tom Peterka10 Feb 2005CS 522 The primary study consisted of 2 tasks: a reading comprehension test and the Guilford-Zimmerman (G-Z) spatial orientation test. Imagine a camera fixed to the bow of the boat. Select the proper change in orientation symbols. Use exocentric or egocentric point of view. Fig. 3

12. John Bell and Tom Peterka10 Feb 2005CS 522 The large display produced better test scores on the spatial test and no difference on the reading test. 2(size) x 2(position) x 2(gender) RM-ANOVA. F(1,20) = 9.470, p =.006 Fig. 4 55.4% 43.8%

13. John Bell and Tom Peterka10 Feb 2005CS 522 The follow-up study was a modified shape test. 24 college students modified shape test x G-Z test x display size Exocentric view for shape test Egocentric view for G-Z test Fig. 5

14. John Bell and Tom Peterka10 Feb 2005CS 522 The large display produced better test scores on the G-Z test and little difference on the shape test. 2(size) x 2(position) x 2(task type) RM-ANOVA F(1,21) = 5.512, p =.0288 large display improves the G-Z test more than the shape test. Fig. 6 53.2% 42.9% 40.8% 39.5%

15. John Bell and Tom Peterka10 Feb 2005CS 522 Three conclusions can be drawn from the 2D tests. 1. No benefit is gained from a larger display for reading comprehension. 2. A larger display is better for 2D orientation tasks such as the G-Z test. 3. A larger display benefits egocentric tasks such as the G-Z test more than it does exocentric tasks such as the shape test.

16. John Bell and Tom Peterka10 Feb 2005CS 522 Large displays are better in 3D. Tan et al., “Physically Large Displays Improve Path Integration in 3D Virtual Navigation Tasks,” CHI 04. Equipment is the same as the 03 paper.

17. John Bell and Tom Peterka10 Feb 2005CS 522 The new task involves navigation in an immersive 3D ( VR ) environment, with motion cues but no navigational landmarks.

18. John Bell and Tom Peterka10 Feb 2005CS 522 Users must path-integrate two sides, and then wayfind back to the origin without the posts displayed.

19. John Bell and Tom Peterka10 Feb 2005CS 522 Other Experimental Notes Users could only turn at the vertices, BUT they could back up and change their angle if they did not like the results. Users received practice trials with unique triangles and an overhead map, with the warning that the map would not be available during the actual tests.

20. John Bell and Tom Peterka10 Feb 2005CS 522 The authors postulate 3 hypotheses: 1.Users will perform better in path integration using large displays, due to increased likelihood of egocentric strategies. 2.Users will perform better in path integration when using active navigation. 3.Display size and interactivity mode are independent effects.

21. John Bell and Tom Peterka10 Feb 2005CS 522 Experimental design was 2 x 2 x 6 trials. 3 dependent variables Two display sizes – large & small Two navigation modes for the first 2 legs – active & passive Six triangles – 60°, 90°, 120°, and 5 or 3m second leg 24 trials / user; 384 total trials. Participants were 16 college students ( 8 male ), 19 to 29, with normal eyesight, average to experienced computer users, who played less than 1 hr / week 3D games. Display size / interactivity mode balanced for confounding effects. Triangles were fully randomized.

22. John Bell and Tom Peterka10 Feb 2005CS 522 Larger displays were significantly better. display size: F(1,339)=11.24p<.001 2.88m vs. 3.48m interactivity: F(1,339)=12.38p<.001 2.87m vs. 3.49m Fig. 6 Mixed model ANOVA (display size x interactivity x gender)

23. John Bell and Tom Peterka10 Feb 2005CS 522 Unpacking component errors helps clarify significant and insignificant correlations. + positive correlation (significant) -negative correlation (significant) 0no correlation (not significant)

24. John Bell and Tom Peterka10 Feb 2005CS 522 A follow-up study explored whether errors were cognitive wayfinding or physical locomotion errors. Users were guided a specified distance, and told the specific angle to turn. ( 3 to 8 m. and 60, 90, 120, or 150 degrees. ) Only the small display and active navigation were investigated. ( The combination with the largest errors in the original experiments. ) Eight ( 4 male ) students participated, who had not participated in the first study, but with similar demographic characteristics.

25. John Bell and Tom Peterka10 Feb 2005CS 522 Results indicate that earlier errors were cognitive, not locomotive. With 95% confidence, distance to origin error was 0.31 to 0.39 m., distance moved error was 0.18 to 0.22 m., and angle turned error was 2.31 to 2.75 degrees. Mean errors in original experiment were 3.78 m., 1.71 m., and 31.52 degrees respectively. Conclusion: Locomotive errors were a small portion of the overall error observed.

26. John Bell and Tom Peterka10 Feb 2005CS 522 The authors arrived at 3 conclusions. Bigger is better: given similar FOV, larger screen size promotes an egocentric point of view resulting in improved wayfinding. Interactivity does not necessarily improve wayfinding; in fact it may prove to be a distraction to wayfinding. Wayfinding errors are cognitive rather than mechanical.

27. John Bell and Tom Peterka10 Feb 2005CS 522 We have a few unanswered questions. If interactivity was not statistically correlated to the component errors, should it be statistically correlated to the resultant total error? Head mounted displays are the other extreme of display size with similar visual angle. Could or should this display medium also be included in the experiment? What effect do the borders around the LCD monitor have on ego/exocentric viewpoint? ( Assuming projection screen is borderless. )

28. John Bell and Tom Peterka10 Feb 2005CS 522 We have more unanswered questions. ( continued ) The LCD is in the user’s foreground ( ie., there is space behind it ) while the projection wall is in the user’s background ( ie., at the horizon ). What effect does this have on viewpoint? If the distance traveled was consistently short, is there some underlying phenomenon that is causing the underestimation of distance? E.g., Is the undershoot in distance actually perceptually constant, but scaled longer in the small display because the same perceptual error represents a longer distance in world space?

29. John Bell and Tom Peterka10 Feb 2005CS 522 References Desney S. Tan, Darren Gergle, Peter G. Scupelli, Randy Pausch, “Physically Large Displays Improve Path Integration in 3D Virtual Navigation Tasks”, CHI 2004. Desney S. Tan, Darren Gergle, Peter G. Scupelli, Randy Pausch, “With Similar Visual Angles, Larger Displays Improve Spatial Performance”, CHI 2003. Desney S. Tan, Jeanine K. Stefanucci, Dennis R. Proffitt, Randy Pausch, “The Infocockpit: Providing Location and Place to Aid Human Memory”, PUI 2001. Blair MacIntyre, Elizabeth D. Mynatt, Stephen Voida, Klaus M. Hansen, Jope Tullio, Gregory M. Corso, “Support for Multitasking and Background Awareness Using Interactive Peripheral Displays”, UIST 2001. Patrick Baudisch, Nathanial Good, Victoria Bellotti, Pamela Scraedley, “Keeping Things in Context: A comparative Evaluation of Focus Plus Context Screens, Overviews, and Zooming”, CHI 2002. George Robertson, Maarten van Dantzich, Daniel Robbins, Mary Czerwinski, Ken Hinckley, Kirsten Risden, David Thiel, Vadim Gorokhovsky, “The Task Gallery: A 3D Window Manager”, CHI 2000.

30. L ARGE D ISPLAYS I MPROVE 2 D AND 3 D N AVIGATION By JOHN BELL and TOM PETERKA University of Illinois at Chicago CS 522 Human Computer Interaction Professor Moher, Spring 2005 10 February 2005