The Effect of Mouse Scroll-wheel Configuration on Virtual Globe NavigationAmenity ApplewhiteYikalo HayelomJia Wang

Usability Study

Outline• Introduction

• Motivation

• Hypothesis

• Study Methodology

• Results & Discussion

• Conclusion

• Recommendation2

Introduction: Mouse Zoom Available in many applications:

Microsoft Office, AutoCAD, ArcMap, Photoshop...

Default setting:

• “Push” forward

• “Pull” back

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Introduction: Virtual Globes • Streaming satellite imagery in 3D

• Zoomable User Interface ZUIinformation navigation best supported by natural and geographic ways of thinking*

4*Perlin & Fox 1993

Introduction: Virtual Globes Four ways to zoom:

• Double-click

• Mouse scroll-wheel 5

Introduction: Virtual Globes Four ways to zoom:

• Double-click

• Mouse scroll-wheel 5

Introduction: Virtual Globes Four ways to zoom:

• Double-click

• Mouse scroll-wheel 5

Motivation• Increasing popularity of virtual globes

• Main ZUI navigation problem: users may get “lost” while zooming*

• Need to provide intuitive tools for a usable interface

Compare the usability of two zoom configurations.

6*Buring, et al 2006

MethodologyHypothesis

Despite the fact that most software shares the same default setting for mouse zooming, users will be able to adjust to the default configuration without a marked decrease in usability.

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MethodologyUsability (adapted from Nielsen)

Learnability ease of accomplishing task the first time

Errors number of errors and ease of recovery

Satisfaction pleasant to use design?

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MethodologyTest design

Participants 6 classmates: 4 males, 2 females; 23-29

Simple task instrucions• 4 screenshots in Google Earth,

pasted into Word

• Instructed only to use mouse wheel for movement

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Methodology

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MethodologyTest design

Two sessions First with default zoom, second reverse

Recorded with CamStudio

Facial expressions and speech noted

Post study interview, scale 1-5• Difficulty

• Enjoyment10

MethodologyTest design

Errors & Learnability• number of errors counted in second

half of tasks in both sessions

• compared results individually

Enjoyment• observed during session

• reported during interview11

MethodologyTest design

Criteria to accept hypothesis• an increase of errors with reverse

configuration no greater than 10%

• no significant decrease in enjoyment - observed or reported

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Results

13

1

2

3

4

5

6

0 0.075 0.150 0.225 0.300

Increase in zoom errors with reverse setting

Use

r

• Difference in errors

with reverse setting

greater than 10%

for 4 users

7.5% 15% 22.5%

Results

13

1

2

3

4

5

6

0 0.075 0.150 0.225 0.300

Increase in zoom errors with reverse setting

Use

r

• Difference in errors

with reverse setting

greater than 10%

for 4 users

7.5% 15% 22.5%

12.38%

20%

20.55%

13.18%

Results• All users performed

more zooms with

reverse setting

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1

2

3

4

5

6

0 20 40 60 80

Total Number of Zooms

Use

r

Test 1 default zoomTest 2 reverse zoom

Results• Two users noticed the change immediately

• One vocalized frustration throughout task with reverse setting

• One user reported that the reverse setting was more difficult

• No one reported the reverse setting was less enjoyable

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ConclusionMust reject hypothesis:

• Increase in errors was greater than 10% for the majority of users; not learnable!

• Reported and observed decrease in enjoyment; not enjoyable!

• Questions raised about efficiency, more zooms

Ultimately, the reverse setting seems to have lower usability. 16

Recommendation• Some users not affected by reverse setting

• Using the scroll wheel instead of double-click was very difficult for some users

• We recommend that virtual globe interfaces offer a range of zooming methods and allow users to adjust the configurations

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ReferencesBüring, T., Gerken, J., and Reiterer, H. 2006. Usability of overview-supported zooming on small screens with regard to individual differences in spatial ability. In Proceedings of the Working Conference on Advanced Visual interfaces (Venezia, Italy, May 23 - 26, 2006). AVI '06. ACM, New York, NY, 233-240.

Perlin, K. and Fox, D. 1993. Pad: an alternative approach to the computer interface. In Proceedings of the 20th Annual Conference on Computer Graphics and interactive Techniques SIGGRAPH '93. ACM, New York, NY, 57-64.

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Questions?

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