6. io device

HUMAN COMPUTER INTERACTION (INTERACTION HOMME-MACHINE) LAY H éng [email_address] 2009 - 2010

CHAPTER 6: INPUT / OUTPUT DEVICES Where we will se there is not only mouse in the world …

INPUT DEVICES: HISTORY REVIEW 1950 1960 1970

INPUT DEVICES: HISTORY REVIEW 1980 1990 2000

INPUT DEVICE 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 Input type Discrete Keyboard … Continuous trackball, joystick, optical stylus … Localization Direct optical stylus, touchscreen … Indirect mouse, trackball, joystick, graphical tablet … Absolute optical stylus, touchscreen, graphical tablet Relative mouse, trackball, joystick …

INPUT DEVICES: KEYBOARD 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) 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 2 nd line balance on both hands Result reduction 90% of movement DVORAK English DVORAK French

INPUT DEVICES: KEYBOARD (DISPOSITION) Natural keyboards DVORAK disposition Curvature keyboard, sculptured keyboard limiting the articulation tension Microsoft Maltron Kinesis 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 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 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 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 Handwriting recognition Error rate is not negligible Input of special symbols: learnabillity, familiarity Unistrokes Graffiti

ADVANCE INPUT DEVICES 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 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 Eye trackers Head movement detection Breath detection Joystick microgravity ... Virtual keyboard Speech recognition …

PREDICTIVE MODEL: GOMS 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 Example Goals Text Editor: delete a word in a phrase Methods Operators Selection

PREDICTIVE METHOD: KEYSTROKE 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 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 T exec = T K + T P + T H + T D + T M + (T R )

PREDICTIVE MODEL: FITTS’S LAW 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 log 2 (2D/d) C1,C2: constant depend on device (example: C1=0.05s and C2=0.1s) and determined by experimentations [Fitts, 1954]

BIBLIOGRAPHIES 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.

6. io device

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