Post on 25-Dec-2015
CHAPTER 9CHAPTER 9
INTERACTION DEVICES
Ben Carson
Rajesh Golla
Sunil Dsouza
IntroductionIntroduction
Advances have yielded more productivity
Future input devices will involve more of
the body: gestures, voice, wearable devices
Advances in computing power have led to advances in input and output devices
Keyboards and Function KeysKeyboards and Function Keys
Different types of keyboard, depending on function used for
Several Key Layouts Keyboard Keys Functions Keys Cursor Movement Keys
Pointing DevicesPointing Devices
Select Position Orient Path Quantify Text
Tasks
Direct Control pointing Direct Control pointing devicesdevices
Lightpen Touchscreen Stylus
Examples Advantages Direct control Easier to learn than
indirect control
Disadvantages
Obscures Screen Arm fatigue
Smudging of display (touchscreen)
Removal of hand from keyboard
Indirect Control pointing Indirect Control pointing devicesdevices
ExamplesMouseTrackballJoystickTrackpointGraphics tabletTouchpad
Advantages Doesn’t obscures screen Less arm fatigue No smudging
Disadvantages Removal of hand from
keyboard Indirect control harder to
learn than direct control
Comparision of pointing Comparision of pointing devicesdevices
Best pointing devices depends on the taskTablet: long periods of being away from keyboard touchscreen/trackball: public access, shop floor,
laboratory applicationsMouse/trackball/tablet/touchpad: pixel-level
pointingKeyboard Cursor keys: moving between a small
number of targetsJoystick/trackball: game and flight sim designers
FITT’S LAWFITT’S LAW Developed by Paul Fitts in 1954
Index of difficulty=log2(2D/W)
Time to Point=C1 + C2(Index of Difficulty)
Sears and ShneidermanTime for precision pointing=
C1+C2(Index of Difficulty)+C3 log2(C4/W)
Novel pointing devicesNovel pointing devices
Foot Mouse Eye-tracking, gaze detection DataGlove Binocular Omni-Orientation Monitor (BOOM) Several variants of 3-D pointing devices Haptic feedback
Speech generation,Digitization and Speech generation,Digitization and recognitionrecognition
Voice commanding : more demanding of users working memory
Background noise Variations in user speech
Very useful for handicapped people
Speech technology
Discrete word recognition Continuous speech recognition Speech store and forward Speech generation
All of them can be combined in creative ways
Discrete Word RecognitionDiscrete Word Recognition
The devices recognize individual words spoken by specific person
Reliability: 90 to 98 percent for 20-200 word vocabulary
Speaker dependent training Speaker independent training Careful choice of employees improves
recognition rates
Applications
Physically handicapped Speakers hands are busy Mobility is required Speakers eyes are occupied
Examples: Aircraft engine inspectors, baggage handlers
Studies show that speech input was not found to be beneficial
Continuous Speech RecognitionContinuous Speech Recognition
Commercially successfully products are restricted to specialty niches such as radiologists
Difficulty is recognizing the boundaries between spoken words
AIM: dictate letters, compose reports verbally, scan long audio tracks, identifications purposes
ProductsProducts
Verbex: 99.5 percent accuracy, speaker dependent training, vocabulary up to 10000 words
Speech systems: 95 percent accuracy, speaker independent training, 40000 word vocabulary
Target tasks: operating system control, police requests for info on car license, stock broker orders
Speech Store and ForwardSpeech Store and Forward
Less exciting- more useful Commonly used for weather, airline, financial
information, personal messaging telephone Voice mail technology Telephone based information systems Personal tape recorders Audio tours in museums
Speech GenerationSpeech GenerationReliable speech generation devices used in
Cameras Soft drink vending machines Automobiles Games
Applications for the blind
Speech generation preferred when
Message is short Message is simple Message will not be referred to later Message deals with events in time Message requires immediate response Visual channels of communications are overloaded Environments unsuitable for visual information User must be free to move around User is subject to high G forces
Other machine outputsOther machine outputs
Audio tones Audiolization Music
Used to give feedback to the used
Warnings or acknowledgements Very helpful for blind users
Image and Video DisplaysImage and Video Displays Features
Rapid Operation
Reasonable size
Reasonable resolution
Quiet Operation
No paper waste
Low Cost
Reliability
Graphics and animation
Display DevicesDisplay Devices
Cathode Ray Tube
Liquid Crystal Displays
Plasma Panel
Light emitting Diodes
Digital Photography and Digital Photography and ScannersScanners
Digi cams Digital storage of photographs Electronic editing and manipulation
Scanners Convert maps,documents and manuscripts into
digital format Optical Character Recognition – convert text in
printed docs to electronic forms
Digital VideoDigital Video
Videodisks 12 inch 54000 still images/30 min video CD-ROMs 600+ mb of data 1 hour videos (depending on codec)DVD’s 2-3 hours of video storage
CODEC’s
Motion Picture Experts Group (MPEG)
RealVideo
H263 - medium-quality videoconferencing
Other DisplaysOther Displays
Projectors 2 by 3 meter displays Good saturation, small loss of fidelity
Heads-up displays video/data on partially silvered windscreen
Helmet Mounted Displays
PrintersPrintersNecessary Features Speed Print Quality Cost Compactness Quite operation Font,character set,size Reliability
SummarySummary
Devices which are cost effective Selecting rather than typing devices Better speech input devices Better video o/p devices.. Higher resolution,
color and larger displays
DESIGN