1

WatchIt: Simple Gestures and Eyes-free Interaction for

Wristwatches and Bracelets

S. Perrault, E. Lecolinet, J. Eagan, Y. GuiardTélécom ParisTech – LTCI CNRS UMR 5141

2

How to interact while…

3

…walking on a crowded street

4

…when your phone is hard to reach

5

…if you need to pay attention to your surrounding

6

Microinteractions

• Named by [Ashbrook2010]– Quick (~3-4 secs)– Punctual– Short interruption

7

Examples of Microinteractions

• Reject call• Check messages• Check location• Check agenda/time• GPS Navigation• Manage music• Etc…

8

Particular example: Music

10 commands + continuous control + list scrolling

9

Where to perform Microinteractions?

10

On the Wrist!

~60% of women & ~40% of men wear bracelets or wristwatches every day.

11

Many Commercial Products

• Permanently on the user• Easy to access

Pebble I’m Watch iWatch?

Interaction on a Wristwatch

• Occlusion• Fat finger problem

• Input/output– Limited– Merged

12

13

[Ashbrook2008][Blasko2004][Baudisch2009]

Existing Solutions

• Bezel• Back of device• Contactless• Device motion

Watchband?[Harrison2009][Rekimoto2001]

14

Novel Solution: Interaction on the Watchband

• Large surface• Tactile feedback• Input/output

separation– No occlusion– No fat finger problem

External band

Internal band

15

Interaction on a Watchband

MOCKUP

16

Implementation: the WatchIt Prototype

• Resistive technology• Advantages:– Low power– Few accidental activations– Not apparent– Cheap

• Drawback:– 1 dimension only

17

Interaction Needs

10 commands + continuous control + list scrolling

18

Eyes-free Interaction

10 commands + continuous control + list scrolling

19

Gestures Technique

• 3 pointing zones– Extremities– Large central zone

• 2 sliding directionsClasp Screen

• Pinching= (3+2)*3 = 15 gestures

External band

Internal band

« Apricot »

Pear

Kiwi

Fig

Banana

Apricot

Audio Menu Technique

• Inspired by earPod [Zhao2007]

• Each band divided in 5 zones

• 1 zone = 1 item• Continuous audio feedback

20

« Fig »

21

Interaction Evaluation

Are users able to perform many commands without looking at the device?

• Gestures vs. Audio Menu• 8 participants• Accuracy & time– Time = reaction + travel + gesture

Audio Menu Technique

• Accuracy 94%– No band effect

• Time– Average 3.2s– Band effect

22

Tim

e (s

)Ac

cura

cy (%

)

External Internal 2-contacts

External Internal 2-contacts22

23

Gestures Technique

• Band effect– Accuracy– Time

• Comparison– Gestures faster– Menu + precise

External Internal 2-contacts 80

85

90

95

100

Accu

racy

(%)

External Internal 2-contacts0

1

2

3

4

Tim

e (s

)

24

List Scrolling

10 commands + continuous control + list scrolling

25

List Scrolling Evaluation

Are users able to scroll lists on the watchband quickly and precisely?

• Navigation task• Touchscreen vs 2 techniques

26

Technique: Relative Scrolling on Watchband

• Same as scrolling on a screen– Pan– Flicking

• More vertical space

ApricotBananaCherry

DatFig

GrapeKiwi

MandarineNut

OrangePeanut

Watermelon

ApricotBananaCherry

DatFig

GrapeKiwi

MandarineNut

OrangePeanut

Watermelon

27

Relative Scrolling Video

28

Technique: Absolute Scrolling on Watchband

• Mapping between:– List space (virtual)– Watchband space (physical)

• Close to screen = Beginning• Close to clasp = End of list

• Instant scrolling• Not very precise for long lists

ApricotBananaCherry

DatFig

GrapeKiwi

MandarineNut

OrangePeanut

Watermelon

29

Absolute Scrolling Video

30

Experimental Design

• Touchscreen active– Selection– Watchband as a complement– User preference & strategy

• 3 list sizes (15/60/240 items)• 6 distances (5, 10, 20, 40, 80, 160 items)• 12 participants

ApricotBananaCherry

DatFig

GrapeKiwi

MandarineNut

OrangePeanut

Watermelon

D =

5 it

ems

31

Results

• Absolute scrolling– Faster on any list

• Relative scrolling– Always slower– Friction?

Short Medium Long0

2

4

6

8

Touch screen

Absolute scrolling bracelet

Relative scrolling bracelet

List size

Nav

igati

on T

ime

(s)

32

Interaction Strategy

• Relative technique:– 1.02 pans/trial on screen

• Absolute technique:– Fast imprecise on watchband– Corrections on screen (1.93/trial)

User Preferences

• Interaction on watchband– More comfortable– No occlusion

• Favorite technique:– Absolute technique (9/12)

33

List Scrolling Findings

• Hybrid technique?– Absolute for fast movement– Relative for adjusting

• Augmented input space– Effective list scrolling– Appreciated by users

34

WatchIt: Takeaway Message

• Micro- and rich interactions– Many commands (10+)– Eyes-free interaction– List scrolling

• Properties:– Increase input space– Input/output space separated

35

36

Thank you! Questions?

The VIA team is looking for postdocs!

37

Mapping from vocabulary to musicCommand Matching gesture

Play/pause Middle position, internal bracelet

Previous Top position, internal bracelet

Next Bottom position, internal bracelet

Volume control (continuous) 2-contact sliding gestures

Position in the song (continuous) Sliding gestures, internal bracelet

Repeat Top, external

Shuffle Middle, external