1. 1 Touch-Sensing Input Devices Ken Hinckley Mike Sinclair Microsoft Research CHI’99 Conf. on Human Factors in Computing Systems

2. 2 What is Touch-Sensing? zInput modality for sensing contact of the bare hand or fingers zTouchpads, touchscreens, touch tablets yTouch, Release events ytouching & positioning tightly coupled… zIgnored by most software & other devices zTechnology is cheap, simple, no calibration

3. 3 Why Do This? zChanging hardware changes all the rules! zSensing enables new UI’s with better awareness of context and thus can potentially both simplify & enhance the user experience. zExtend to desktop devices / computing yBoth implicit & explicit usage

4. 4 Some Examples of Sensing for UI zBuxton: “Proximal Sensing” zHarrison et al., handedness detect on PDA zSliders on mixing consoles zZimmerman et al: Electric field sensing zCameras, Sinks in public restrooms,...

5. 5 Some Examples of Sensing for UI zBuxton: “Proximal Sensing” zHarrison et al., handedness detect on PDA zBuxton: touch-sensitive treadmills zZimmerman et al: Electric field sensing zCameras, Sinks in public restrooms,...

6. 6 The Touch Mouse zSense contact from user’s hand via capacitance zNew events: Touch, Release zWhat is sensed  what the user feels zEmulation from software... yDid user release mouse? Or just holding still? yCannot emulate multiple sensors at all.

7. 7 How the Touch Mouse Works zYour body is a capacitor zSquare wave on surface zHand causes time delay tt

8. 8 What’s a Touch Mouse Good For? zAllocate screen real estate more intelligently yTension: UI always up vs. max doc real estate yMost widgets only useful if you’re holding mouse ySo fade in / out portions of display via touch! zNo retraining necessary zVIDEO

9. 9 Fading out Toolbars zFading chosen as minimally distracting animation zAsymmetric: y.3s fade in y1s fade-out

10. 10 Interaction Style vs. Display-Only Style zSome GUI elements provide visual feedback zThese can fade to compact representation when user isn’t holding the mouse 1 2 3

11. 11 Cursor Feedback zCursor “sonar” on touch ydraws attention to locus of interaction zHide cursor on release

12. 12 Usability Testing Results zInformal usability study with 11 users zTest users loved it: Easy and it just does the right thing y“I like that the toolbar comes up quickly when you need it… and all the extra stuff isn’t there when you don’t need it.” zAlso tried leaving toolbar semi-transparent y“It looks like a wet newspaper.” zPlanning more formal experiment

13. 13 Feedback for Toolbars... zUsers dislike transparent toolbar. zBut it gives useful feedback...

14. 14 Another Example: Explicit Interaction zExplicit usage: intentional gestures for Enhanced scrolling yTapping above/below wheel for Page Up/Down yRoll-and-hold for continuous autoscrolling yReading sensor: Dwell time on wheel (?) yTapping tested very well: paging 4.6 out of 5 yDoesn’t interfere with normal use of wheel xTap-and-hold? Tapping, then resting, is not possible zSame controls more useful on keyboard?

15. 15 What Are Some General Properties of Touch-Sensing? zWhat are touch-sensing devices good for? zWhat are some of the design trade-offs involved? zOur answers so far based on practice & experience, no formal experiments yet.

16. 16 Intentional Control vs. Cognitive & Physical Burden zButton-click  Touch  Hand-near-device zPotential problems? yDecrease in user’s intentional control yIncrease in SW inferential burden (error rates) zUse these “problems” to our advantage! yDecreased cognitive burden to make decisions yTouching is something the user must do anyway zProvide useful services with a low cost from errors of intent / interpretation.

17. 17 Some Important Properties of Touch-Sensing Devices zZero activation force: “accidental” activation. yprone to inadvertent contact for explicit actions zFlexible form factor: It’s paint! ycurved surfaces, tight spaces, moving parts, … zUnobtrusive: near zero vertical profile. zDeactivation from software ycan ignore inputs without giving false “click” feedback

18. 18 Conclusions zWhen matched to appropriate interaction techniques, the unique properties of touch- sensing devices allow user interfaces to effectively support new behaviors. yusers find our techniques compelling and useful zExample of applying sensing technolgies to benefit user interaction zPromising area that needs more work.

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20. 20 Classification of Tactile Input Technologies z Contact type z Discrete/ Continuous z Single/Multiple inputs z Limitations... yTechnology-centric yOnly some sensors yDoesn’t distinguish technologies w/in cell yIgnores position / orientation sensing

21. 21 Traditional Input Devices with Touch zBuxton input taxonomy: devices operated by touch vs. mechanical intermediary zTouchpads, touchscreens, touch tablets ycannot position without touching ynor touch without positioning… zBuxton, Hill, & Rowley: touch-tablets ysenses Touch, Release events; a mouse cannot

22. 22 Similarities to Touch Tablets zOne can potentially confer some desirable properties of touch tablets to the mouse. zBuxton, Hill, & Rowley 1985 zNo moving parts for touch sensors. zNo mechanical intermediary -- use bare hand. zOperation by feel: Tactile cues can correspond to touch-sensitive regions. zAmount & type of feedback. No “click” of a button. yMay be undesirable for implicit interactions anyway.

23. 23 Example Circuit zVery simple! zFor 1 sensor zneed to sync multiple sensors

24. 24 Why Sense Touch? zTouch is important human sensory channel ycontact with objects, pets, people zWhat is sensed  what the user feels zIgnored by most input devices & software zTechnology is cheap, simple, no calibration z= Opportunity!

25. 25 TouchTrackball for ToolGlass Interactions zToolGlass fades in when user touches trackball yToolbars also fade out if they are visible yRelease trackball  Reverts to toolbars (if holding mouse) or clean screen if not.