An Experimental Analysis of Undo in Ubiquitous Computing

Environments

Marco Loregian, Marco P. LocatelliUniversity of Milano-Bicocca (Italy)

Outline

• Problem

• Experiment

• Results

• Ongoing and future work

• Conclusion

Undo

• Well known function of PC applications

• Allows to revert (the effects of) commands

• Applied to user actions

• Different strategies

What does “undo” mean in ubicomp environments?

The problem

• We need to know it in order to design usable (successful) systems

• How should we find it out?

• Undo is a user intention

• We surveyed potential users

The experiment

• Introduction of the problem with a video-scenario

• Multi-part survey

The video

Available on Google Video: “Dude, where is my ctrl-z?”http://video.google.it/videoplay?docid=1025487561314098360

The survey

• Demographics

• What if you were the user?

• What if you were the system?

• How much would it be acceptable to… (17 items)

• Summary of the operations

The results

• Demographics

• Analysis of the applied undo strategies

Full stats are in the paper

Demographics

64%

36%

Gender

M F

0

1

2

3

4

5

6

18 20 22 24 26 28 30 32 34 36 38 40 42 44 46

Age

Mostly university students (psychology)

Analysis

• Users had very different ideas about what undo should be like

• We tried to highlight shared opinions, and to find the factors influencing divergent opinions

• Different preferences = different strategies to be available for being chosen

• Do strategies in literature still apply?

Some hypotheses

• System as a mediator between humans? No, better if not intrusive

• Degree of autonomy?It depends, but must be known in advance by the user

• Collect context information?Yes, but never violate users’ privacy

0

5

10

15

20

Linear Selective Other

Undo strategy implicitly applied by participants#

par

ticip

ants

Analysis according to the definitions in literature

Non-Smart Smart

No Compensation 33% 6%

Compensation 17% 44%

50%

61%

Undo strategy implicitly applied by participants

So what?

• Ubicomp systems must be provided with context-aware, smart (semi-proactive) undo functions, with compensation mechanisms

• It’s not easy! It’s not only a (serious) usability problem

• Designers: keep the problem in mind and interact with users

• Developers: deal with the problem

Ongoing Work

• Undo for

• context-aware collaborative ubiquitous computing environments[to appear at IDC’2008, sept.]

• mobile phones[to appear at NordiCHI 2008, oct.]

• email[in preparation]

Future Work

• Prototyping with the CASMAS framework

• Find scenarios

• Analyze undo in place

• Implement

• Test

Conclusionundo!undo!undo!

Even Homer knows that undo is important!

Thank you!

An Experimental Analysis of Undo in Ubiquitous

Computing EnvironmentsMarco Loregian, Marco P. LocatelliUniversity of Milano-Bicocca (Italy)