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CHAPTER 6:INPUT / OUTPUT DEVICES
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Where we will se there is not only mouse in the world …
INPUT DEVICES: HISTORY REVIEW
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1950 1960
1970
INPUT DEVICES: HISTORY REVIEW
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1980
1990
2000
INPUT DEVICE
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Choosing a good device for the system Multi input devices possible a priori Compromise between contradictory constraints and not only on ergonomic:
no ideal device Utilization jointly many devices: complementary
Example: Mouse + Keyboard Importance of feedback associated to device: do not neglect in the choices
of devices
Example:
move the cursor on the screen
key typing vs. touchscreen
joystick feedback
INPUT DEVICES: TYPOLOGY
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Input type Discrete Keyboard … Continuous trackball, joystick, optical stylus …
Localization Direct optical stylus, touchscreen … Indirect mouse, trackball, joystick, graphical tablet …
Absoluteoptical stylus, touchscreen, graphical tablet Relative mouse, trackball, joystick …
INPUT DEVICES: KEYBOARD
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Keys: pressing type Electro-mechanics good feedback,
less resistance (problem dirty mark)
Membrane resistance, less incident
mediocre feedback
Keys: disposition Essential ergonomic factor: quick input, fatigue the articulation and
muscles … However, a solution under optimal: keyboard AZERTY / QWERTY
Remark: less than 15 days to adapt to the new keyboard
INPUT DEVICES: KEYBOARD (DISPOSITION)
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QWERTY / AZERTY 1874 typewriter: jamming hammer Non ergonomic coupling the separated keys
most frequent keys on the left
DVORAK 1932 vowels and frequent consonant on 2nd line
balance on both hands Result reduction 90% of movement
DVORAK English DVORAK French
INPUT DEVICES: KEYBOARD (DISPOSITION)
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Natural keyboards DVORAK disposition Curvature keyboard, sculptured keyboard limiting the articulation tension
Micro
soft M
altron Kin
esis
Chord keyboard Combination of keys to input a character: reduce the number
of keys Industry: one hand input Used to transcripts of debates in some parliament or courts
POINTING DEVICES
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Localization Direct optical stylus, touchscreen Indirect mouse, trackball, joystick, graphical tablet …
Mouse, trackball, touchpad Indication of an localization Indication of a movement
Remark: facilitate the use of an input device by software constraints
Hybrid interaction style (click + localization) more grid of discrete position to draw geometric figure using a mouse
Microsoft trackball+
Optical mouse
POINTING DEVICES
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Touch screen Direct interaction Extreme facility of learning Resistant and without movable extern element (devices)
_________________________________________________
Lack of precision (error of pointing) New screen with high precision, stylus
Fatigue arm / hand Screen with horizontal position
Screen masking Stylus
Optical stylus
ADVANCE INPUT DEVICES
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Handwriting recognition Fusion of different modalities of input
Text input and pointing with only one device: touch screen
Direct interaction Natural language: learning facility
ADVANCE INPUT DEVICES
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Handwriting recognition Error rate is not negligible
Input of special symbols: learnabillity, familiarity
Unistrokes Graffiti
ADVANCE INPUT DEVICES
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Speech recognition Natural interaction style Absent of particular device: hand free, telephony
______________________________________________________________ High error rate
5% of WER in reading and finalized spontaneous speech (DOHM) 30% to 50% of WER in generic spontaneous speech
Ambiguity of natural language Replace the keyboard Problem of design too anthropomorphic
______________________________________________________________
Research and some well targeting applications Medical reports Reservation and Information server (ex: 3000)
ADVANCE INPUT DEVICES
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Gloves and other 3D devices Increase virtual reality Hot research Some applications: video game, simulators, telemedicine Future technique and dream of researcher?
3D glove (data glove) Haptic glove (force feedback or gesture)
INPUT DEVICES FOR HANDICAPPED
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Eye trackers Head movement detection Breath detection Joystick microgravity ...
Virtual keyboard Speech recognition …
PREDICTIVE MODEL: GOMS
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Predictive model Measure predictive the behavior of user without real test Base on the result in psychology cognitive Useful for conception and evaluation
GOMS Goals – goals/objectives that user want to achieve Methods – procedure (sequence of actions or cognitive activities)
required to accomplish the goals Operators – cognitive process and physic actions taken at the end of
different possible methods Selection – rules used to choose a method in a giving moment
Estimate the execution time base on average known time for each operator
[Card, Moran, Newell, 1983]
PREDICTIVE MODEL: GOMS
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Example Goals Text Editor: delete a word in a phrase Methods
Operators
Selection
PREDICTIVE METHOD: KEYSTROKE
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Keystroke level model Independent of GOMS Estimate the execution time of basic commands Model base on the observation of multiple experimental data on the time to
complete the elementary operators
Operators K Key selection (keystroke) P Pointing H reposition of hand on input device D display/drawing a line on the screen M mental action R (eventual) response time of system
[Card, Moran, Newell, 1983]
PREDICTIVE MODEL: KEYSTROKE
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Operators: average execution time K simple key press
Experienced secretary input
Average user input
Novice user input
Press <Shift> or <Ctrl> P Mouse pointing on a target
mouse click H reposition of keyboard D drawing a line M mental action
Texec = TK + TP + TH + TD + TM + (TR)
PREDICTIVE MODEL: FITTS’S LAW
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Principle
The time taken to achieve a target is proportional to the distance of the target and inversely proportional to its size
Law
The necessary time to move a pointing device which is placed at a distance D from the target of larger d:
Limits Limit of scale – beyond a certain critical value of distance D, the time
required to reach the target will just depend on D, instead of the D/d Limit of difficulty – for ratio D/d well above 1000, achieving the target is
generally not possible (subject failure) Limit of device – law does not valid for all types of pointing devices
T = C1 + C2 log2(2D/d)
C1,C2: constant depend on device (example: C1=0.05s and C2=0.1s) and determined by experimentations
[Fitts, 1954]
BIBLIOGRAPHIES
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Publications Card S., Moran T., Newell A. (1983) The psychology of Human-Computer
Interaction, Laurence Erlbaum Ass., Hillsdale, NJ. Fitts P.M. (1954) The information capacity of the human motor system in
controlling amplitude of movement. Journal of Experimental Psychology. 47, 381-391.
Gray W.D., John B.E., Atwood M.E. (1993) Project Ernestine: validating a GOMS analysis for predicting and explaining real-world performance. Human-Computer Interaction. 8(3), 237-309.
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