Understanding & Modeling Input Devices

Transcription

1 cs147 October 6, 2009 Understanding & Modeling Input Devices Björn Hartmann

2 HW3 rubric clarified Google groups 2

3 1. How do common input devices work? 2. How can we think about the larger space of all possible input devices? 3. Can we predict human input performance? 4. What about uncommon input devices (multitouch, tangible interfaces, )? 5. Will this be on the exam? Yes. 3

4 Level of abstraction abstract models Functional Dissection of Mouse & Keyboard Design Space of Input Devices Modeling Human Performance concrete details time 4

5 I think my keyboard is broken. Whenever I have a few keys pressed down, some keys suddenly don t work anymore; at other times phantom characters appear. What s going on?

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8 Key cap Separating layer (with hole) Top conductive layer Bottom conductive layer

9 Key cap Separating layer (with hole) Top conductive layer Bottom conductive layer

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11 9 lines C1 C2 C3 C4 C5 20 keys R1 Q W E R T R2 A S D F G R3 Z X C V B R4 11

12 C1 C2 R1 R2 12

13 C1 C2 R1 R2 13

14 C1 C2 R1 R2 14

15 C1 C2 R1 R2 15

16 C1 C2 R1 R2 16

17 A Layered Framework From: Hartmann, Follmer, Klemmer: Input Devices are like Onions 17

18 Source: Card, Stu. Lecture on Human Information Interaction. Stanford, Mouse. Engelbart and English ~1964

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21 Right button Encoder wheel for scrolling Left button 21

22 slotted wheel (between emitter & detector) IR emitter IR detector 22

23 High 23

24 Low 24

25 Low Oops! 25

26 High High 26

27 Low High 27

28 Coding: HH-> LH: dx = 1 HH-> HL: dx = -1 High Low 28

29 cx t = max(0, min( sw, cx t-1 +dx*cd )) cy t = cx t : cursor x position in screen coordinates at time t dx: mouse x movement delta in mouse coordinates sw: screen width cd: control-display ratio 29

30 Click, DoubleClick, MouseUp, MouseDown, MouseMove 30

31 Source: 31

32 Source: 32

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34 Indirect, force sensing, velocity control Nonlinear transfer function Velocity Force (cc) Image by flickr user tsaiid

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36 A design space of input devices Card, S. K., Mackinlay, J. D., and Robertson, G. G A morphological analysis of the design space of input devices. ACM TOIS 9, 2 (Apr. 1991),

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39 Source: Card, Stu. Lecture on Human Information Interaction. Stanford, 2007.

40 Engelbart Source: Card, Stu. Lecture on Human Information Interaction. Stanford, 2007.

41 Source: Card, Stu. Lecture on Human Information Interaction. Stanford, 2007.

42 Exam Question Material! Time T pos to move the hand to target size S which is distance D away is given by: T pos = a + b log 2 (D/S + 1) Index of Difficulty (ID) Only relative precision matters Source: Landay, James. Human Abilities. CS160 UC Berkeley.

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44 Exam Question Material! Time T pos to move the hand to target size S which is distance D away is given by: T pos = a + b log 2 (D/S + 1) Device Characteristics (bandwidth of human muscle group & of device) a: start/stop time b: speed Source: Landay, James. Human Abilities. CS160 UC Berkeley.

45 Source: Card, Stu. Lecture on Human Information Interaction. Stanford, 2007.

46 Movement Time (sec) Mouse T = log 2 (D/S +.5) sec Why these results? Time to position mouse proportional to Fitts Index of Difficulty I D. [i.e. how well can the muscles direct the input device] Therefore speed limit is in the eye-hand system, not the mouse I D =log (Dist/Size +.5) Source: Card, Stu. Lecture on Human Information Interaction. Stanford, Therefore, mouse is a near optimal device.

47 Which will be faster on average? pie menu (bigger targets & less distance) Source: Landay, James. Human Abilities. CS160 UC Berkeley.

48 Windows 95: Missed by a pixel Windows XP: Good to the last drop The Apple menu in Mac OS X v10.4 Tiger. Source: Jensen Harris, An Office User Interface Blog : Giving You Fitts. Microsoft, 2007; Apple

49 Larger, labeled controls can be clicked more quickly Magic Corner: Office Button in the upper-left corner Mini Toolbar: Close to the cursor Source: Jensen Harris, An Office User Interface Blog : Giving You Fitts. Microsoft, 2007.

50 Assumptions so far: Single user, working in front of a desktop PC Main tasks are typing and pointing Efficiency rules What if we change these assumptions? Design for enjoyment / engagement Design for multi-user scenarios 50

51 Source: Nintendo, us.wii.com

52 Source: Kimiko Ryokai, 52

53 Jeff Han, Perceptive Pixel

54 Hartmann, Björn, Morris, M.R., Benko, H., and Wilson, A. Augmenting Interactive Tables with Mice & Keyboards. In Proceedings of UIST

55 Hartmann, Björn, Morris, M.R., Benko, H., and Wilson, A. Augmenting Interactive Tables with Mice & Keyboards. In Proceedings of UIST

56 Mouse 2.0: Multi-touch Meets the Mouse Nicolas Villar, Shahram Izadi, Dan Rosenfeld, Hrvoje Benko, John Helmes, Jonathan Westhues, Steve Hodges, Eyal Ofek, Alex Butler, Xiang Cao and Billy Chen. Proceedings of UIST

57 cs147 October 6,