WatchIt: Simple Gestures and Eyes-free Interaction for Wristwatches and Bracelets S. Perrault, E. Lecolinet, J. Eagan, Y. Guiard Télécom ParisTech – LTCI CNRS UMR

How to interact while… 2

…walking on a crowded street 3

…when your phone is hard to reach 4

…if you need to pay attention to your surrounding 5

Microinteractions Named by [Ashbrook2010] – Quick (~3-4 secs) – Punctual – Short interruption 6

Examples of Microinteractions Reject call Check messages Check location Check agenda/time GPS Navigation Manage music Etc… 7

Particular example: Music 10 commands + continuous control + list scrolling 8

Where to perform Microinteractions? 9

On the Wrist! ~60% of women & ~40% of men wear bracelets or wristwatches every day. 10

Many Commercial Products Permanently on the user Easy to access 11 PebbleIm WatchiWatch?

Interaction on a Wristwatch Occlusion Fat finger problem Input/output – Limited – Merged 12

[Ashbrook2008] [Blasko2004] [Baudisch2009] Existing Solutions Bezel Back of device Contactless Device motion Watchband? 13 [Harrison2009][Rekimoto2001]

Novel Solution: Interaction on the Watchband Large surface Tactile feedback Input/output separation – No occlusion – No fat finger problem 14 External band Internal band

Interaction on a Watchband 15 MOCKUP

Implementation: the WatchIt Prototype Resistive technology Advantages: – Low power – Few accidental activations – Not apparent – Cheap Drawback: –1 dimension only 16

Interaction Needs 10 commands + continuous control + list scrolling 17

Eyes-free Interaction 10 commands + continuous control + list scrolling 18

Gestures Technique 19 3 pointing zones – Extremities – Large central zone 2 sliding directions Clasp 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 »

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 21

Audio Menu Technique Accuracy 94% – No band effect Time – Average 3.2s – Band effect 22 Time (s) Accuracy (%) ExternalInternal2-contacts ExternalInternal2-contacts 22

Gestures Technique Band effect – Accuracy – Time Comparison – Gestures faster – Menu + precise 23

List Scrolling 10 commands + continuous control + list scrolling 24

List Scrolling Evaluation Are users able to scroll lists on the watchband quickly and precisely? Navigation task Touchscreen vs 2 techniques 25

Technique: Relative Scrolling on Watchband Same as scrolling on a screen – Pan – Flicking More vertical space 26 Apricot Banana Cherry Dat Fig Grape Kiwi Mandarine Nut Orange Peanut Watermelon Apricot Banana Cherry Dat Fig Grape Kiwi Mandarine Nut Orange Peanut Watermelon

Relative Scrolling Video 27

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 28 Apricot Banana Cherry Dat Fig Grape Kiwi Mandarine Nut Orange Peanut Watermelon

Absolute Scrolling Video 29

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 30 Apricot Banana Cherry Dat Fig Grape Kiwi Mandarine Nut Orange Peanut Watermelon D = 5 items

Results Absolute scrolling – Faster on any list Relative scrolling – Always slower – Friction? 31

Interaction Strategy Relative technique: – 1.02 pans/trial on screen Absolute technique: – Fast imprecise on watchband – Corrections on screen (1.93/trial) 32

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

Thank you! Questions? 36 The VIA team is looking for postdocs!

Mapping from vocabulary to music 37 CommandMatching gesture Play/pauseMiddle position, internal bracelet PreviousTop position, internal bracelet NextBottom position, internal bracelet Volume control (continuous)2-contact sliding gestures Position in the song (continuous)Sliding gestures, internal bracelet RepeatTop, external ShuffleMiddle, external