Interaction devices in human Computer Interface(Human Computer interface tutorials)- 2014-2015
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Transcript of Interaction devices in human Computer Interface(Human Computer interface tutorials)- 2014-2015
Interaction Devices
Daroko blog:
• Daroko Blog-trending business and technology
Interaction Performance• 60s vs. Today
– Performance• Hz -> GHz
– Memory• k -> GB
– Storage• k -> TB
– Input• punch cards -> • Keyboards, Pens, tablets, mobile
phones, mice, digital cameras, web cams– Output
• 10 character/sec• Megapixel displays, color laser, surround
sound, force feedback, VR
• Substantial bandwidth increase!
Interaction Performance• Future?
– Gestural input– Two-handed input– 3D I/O– Others: voice, wearable, whole
body, eye trackers, data gloves, haptics, force feedback
– Engineering research!– Entire companies created around
one single technology• Current trend:
– Multimodal (using car navigation via buttons or voice)
– Helps disabled (esp. those w/ different levels of disability)
Keyboard and Keypads
• QWERTY keyboards been around for a long time– (1870s – Christopher Sholes)– Cons: Not easy to learn– Pros: Familiarity– Stats:
• Beginners: 1 keystroke per sec• Average office worker: 5
keystrokes (50 wpm)• Experts: 15 keystrokes per sec
(150 wpm)
• Is it possible to do better? Suggestions?
Keyboard and Keypads• Look at the piano for possible
inspiration• Court reporter keyboards (one
keypress = multiple letters or a word) – 300 wpm, requires extensive
training and use• Keyboard properties that matter
– Size • large - imposing for novices,
appears more complex• mobile devices
– Adjustable• Reduces RSI, better performance
and comfort– Mobile phone keyboards,
blackberry devices, etc.
Keyboard Layouts• QWERTY
– Frequently used pairs far apart– Fewer typewriter jams– Electronic approaches don’t jam.. why use
it?• DVOARK (1920s)
– 150 wpm->200 wpm– Reducing errors– Takes about one week to switch– Stops most from trying
• ABCDE – style– Easier for non-typists– Studies show no improvement vs. QWERTY
• Number pads– What’s in the top row? – Look at phones (slight faster), then look at
calculators, keypads• Those for disabled
– Split keyboards– KeyBowl’s orbiTouch (screenshot)– Eyetrackers, mice– Dasher - 2d motion with word prediction
Keys• Current keyboards have been
extensively tested– Size– Shape– Required force– Spacing
• Speed vs. error rates for majority of users
• Distinctive click gives audio feedback– Why membrane keyboards are
slow (Atari 400?)• Environment hazards might
necessitate • Usually speed is not a factor
Keys Guidelines• Special keys should be denoted• State keys (such as caps, etc.)
should have easily noted states• Special curves or dots for home
keys for touch typists• Inverted T Cursor movement keys
are important (though cross is easier for novices)
• Auto-repeat feature– Improves performance, but only if
repeat is customizable (motor impaired, young, old)
• Two thinking points:– Why are home keys fastest to
type?– Why are certain keys larger?
(Enter, Shift, Space bar)• This is called Fitt’s Law
Keypads for small devices• PDAs, Cellphones, Game consoles• Fold out keyboards• Virtual keyboard• Cloth keyboards (ElekSen)• Haptic feedback?• Mobile phones
– Combine static keys with dynamic soft keys– Multi-tap a key to get to a character– Study: Predictive techniques greatly improve
performance– Ex. LetterWise = 20 wpm vs 15 wpm multitap
• Draw keyboard on screen and tap w/ pen– Speed: 20 to 30 wpm (Sears ’93)
• Handwriting recognition (still hard)– Subset: Graffiti2 (uses unistrokes)
Pointing Devices• Direct manipulation needs some pointing device• Factors:
– Size of device– Accuracy– Dimensionality
• Interaction Tasks:– Select – menu selection, from a list– Position – 1D, 2D, 3D (ex. paint)– Orientation – Control orientation or provide direct 3D
orientation input– Path – Multiple poses are recorded
• ex. to draw a line– Quantify – control widgets that affect variables– Text – move text
• Faster w/ less error than keyboard• Two types (Box 9.1)
– Direct control – device is on the screen surface (touchscreen, stylus)
– Indirect control – mouse, trackball, joystick, touchpad
Direct-control pointing• First device – lightpen
– Point to a place on screen and press a button
– Pros: • Easy to understand and use• Very fast for some operations (e.g. drawing)
– Cons: • Hand gets tired fast! • Hand and pen blocks view of screen• Fragile
• Evolved into the touchscreen – Pros: Very robust, no moving parts– Cons: Depending on app, accuracy could
be an issue • 1600x1600 res with acoustic wave
– Must be careful about software design for selection (land-on strategy).• If you don’t show a cursor of where you are
selecting, users get confused– User confidence is improved with a good
lift-off strategy
Direct-control pointing
• Primarily for novice users or large user base
• Case study: Disney World• Need to consider those
who are: disabled, illiterate, hard of hearing, errors in usage (two touch points), etc.
Indirect-Control Pointing• Pros:
– Reduces hand-fatigue – Reduces obscuration problems
• Cons: – Increases cognitive load – Spatial ability comes more into play
• Mouse– Pros:
• Familiarity• Wide availability• Low cost• Easy to use• Accurate
– Cons:• Time to grab mouse• Desk space• Encumbrance (wire), dirt• Long motions aren’t easy or obvious (pick up and replace)
– Consider, weight, size, style, # of buttons, force feedback
Indirect-Control Pointing• Trackball– Pros:
• Small physical footprint• Good for kiosks
• Joystick– Easy to use, lots of buttons– Good for tracking (guide or
follow an on screen object)– Does it map well to your app?
• Touchpoint– Pressure-sensitive ‘nubbin’ on
laptops– Keep fingers on the home
position
Indirect-Control Pointing
• Touchpad– Laptop mouse device– Lack of moving parts, and
low profile– Accuracy, esp. those w/
motor disabilities• Graphics Tablet– Screen shot– comfort– good for cad, artists– Limited data entry
Comparing pointing devices• Direct pointing
– Study: Faster but less accurate than indirect (Haller ’84)• Lots of studies confirm mouse is best for most tasks for speed
and accuracy• Trackpoint < Trackballs & Touchpads < Mouse• Short distances – cursor keys are better• Disabled prefer joysticks and trackballs
– If force application is a problem, then touch sensitive is preferred– Vision impaired have problems with most pointing devices
• Use multimodal approach or customizable cursors• Read Vanderheiden ’04 for a case study
• Designers should smooth out trajectories• Large targets reduce time and frustration
Example• Five fastest places to click on for a right-handed
user?
Example• What affects time?
Fitts’s Law• Paul Fitts (1954) developed a model of human hand
movement• Used to predict time to point at an object• What are the factors to determine the time to point to an
object?– D – distance to target– W – size of target
• Just from your own experience, is this function linear?– No, since if Target A is D distance and Target B is 2D distance,
it doesn’t take twice as long– What about target size? Not linear there either
• MT = a + b log2(D/W + 1)– a = time to start/stop in seconds (empirically measured
per device)– b = inherent speed of the device (empirically measured
per device)– Ex. a = 300 ms, b = 200 ms/bit, D = 14 cm, W = 2 cm
• Ans: 300 + 200 log2(14/2 + 1) = 900 ms– Really a slope-intercept model
Fitts’s Law• MT = a + b log2(D/W + 1)– a = time to start/stop in seconds (empirically measured per
device)– b = inherent speed of the device (empirically measured per
device)– Ex. a = 300 ms, b = 200 ms/bit, D = 14 cm, W = 2 cm
• Ans: 300 + 200 log2(14/2 + 1) = 900 ms– Question: If I wanted to half the pointing time (on average), how much
do I change the size?• Proven to provide good timings for most age groups• Newer versions taken into account
– Direction (we are faster horizontally than vertically)– Device weight– Target shape– Arm position (resting or midair)– 2D and 3D (Zhai ’96)
Very Successfully Studied• Applies to
– Feet, eye gaze, head mounted sights– Many types of input devices– Physical environments (underwater!)– User populations (even retarded and drugged)– Drag & Drop and Point & Click
• Limitations– Dimensionality– Software accelerated pointer motion– Training– Trajectory Tasks (Accot-Zhai Steering Law)– Decision Making (Hick’s Law)
• Results (what does it say about)– Buttons and widget size?– Edges?– Popup vs. pull-down menus– Pie vs. Linear menus– iPhone/web pages (real borders) vs. monitor+mouse (virtual borders)
• Interesting readings:– http://particletree.com/features/visualizing-fittss-law/– http://www.asktog.com/columns/022DesignedToGiveFitts.html– http://www.yorku.ca/mack/GI92.html
Precision Pointing Movement Time
• Study: Sears and Shneiderman ’91 – Broke down task into gross and fine components for small targets– PPMT = a + b log2(D/W+1) + c log2(d/W)
• c – speed for short distance movement• d – minor distance
– Notice how the overall time changes with a smaller target.• Other factors
– Age (Pg. 369)• Research: How can we design devices that produce smaller
constants for the predictive equation– Two handed– Zooming
Novel Devices• Themes:
– Make device more diverse• Users• Task
– Improve match between task and device
– Improve affordance– Refine input– Feedback strategies
• Foot controls– Already used in music where
hands might be busy– Cars– Foot mouse was twice as slow as
hand mouse– Could specify ‘modes’
Novel Devices• Eye-tracking
– Accuracy 1-2 degrees– selections are by constant stare
for 200-600 ms– How do you distinguish w/ a
selection and a gaze?– Combine w/ manual input
• Multiple degree of freedom devices– Logitech Spaceball and
SpaceMouse– Ascension Bird– Polhemus Liberty and IsoTrack
Novel Devices• Boom Chameleon
– Pros: Natural, good spatial understanding
– Cons: limited applications, hard to interact (very passive)
• DataGlove– Pinch glove– Gesture recognition– American Sign Language,
musical director– Pros: Natural– Cons: Size, hygiene, accuracy,
durability
Novel Devices• Haptic Feedback
– Why is resistance useful?– SensAble Technology’s Phantom– Cons: limited applications– Sound and vibration are easier and can
be a good approximation• Rumble pack
• Two-Handed input– Different hands have different precision– Non-dominant hand selects fill, the
other selects objects• Ubiquitous Computing and Tangible
User Interface– Active Badges allows you to move
about the house w/ your profile– Which sensors could you use?– Elderly, disabled– Research: Smart House– Myron Kruger – novel user
participation in art (Lots of exhibit art at siggraph)
Novel Devices
• Paper/Whiteboards– Video capture of annotations– Record notes (special tracked pens
Logitech digital pen)
• Handheld Devices– PDA– Universal remote– Help disabled
• Read LCD screens• Rooms in building• Maps
– Interesting body-context-sensitive. • Ex. hold PDA by ear = phone call
answer.
Novel Devices
• Miscellaneous– Shapetape – reports 3D
shape. • Tracks limbs
• Engineer for specific app (like a gun trigger connected to serial port)– Pros: good affordance– Cons: Limited general use,
time
Speech and Auditory Interfaces• There’s the dream• Then there’s reality• Practical apps don’t really require freeform
discussions with a computer– Goals:
• Low cognitive load• Low error rates
• Smaller goals:– Speech Store and Forward (voice mail)– Speech Generation– Currently not too bad, low cost, available
Speech and Auditory Interfaces• Bandwidth is much lower than visual displays• Ephemeral nature of speech (tone, etc.)• Difficulty in parsing/searching (Box 9.2)• Types
– Discrete-word recognition– Continuous speech– Voice information– Speech generation– Non-speech auditory
• If you want to do research here, lots of research in the audio, audio psychology, and DSP field you should understand
Discrete-Word Recognition• Individual words spoken by a specific person• Command and control• 90-98% for 100-10000 word vocabularies• Training
– Speaker speaks the vocabulary– Speaker-independent
• Still requires– Low noise operating environment– Microphones– Vocabulary choice– Clear voice (language disabled are hampered, stressed)– Reduce most questions to very distinct answers (yes/no)
Discrete-Word Recognition• Helps:
– Disabled– Elderly– Cognitive challenged– User is visually distracted– Mobility or space restrictions
• Apps:– Telephone-based info
• Study: much slower for cursor movement than mouse or keyboard (Christian ’00)
• Study: choosing actions (such as drawing actions) improved performance by 21% (Pausch ’91) and word processing (Karl ’93)– However acoustic memory requires high cognitive load (> than hand/eye)
• Toys are successful (dolls, robots). Accuracy isn’t as important• Feedback is difficult
Continuous Speech Recognition• Dictation• Error rates and error repair are still poor• Higher cognitive load, could lower overall quality• Why is it hard?
– Recognize boundaries (normal speech blurs them)– Context sensitivity– “How to wreck a nice beach”
• Much training• Specialized vocabularies (like medical or legal)• Apps:
– Dictate reports, notes, letters– Communication skills practice (virtual patient)– Automatic retrieval/transcription of audio content (like radio, CC)– Security/user ID
Voice Information Systems• Use human voice as a source of info• Apps:
– Tourist info– Museum audio tours– Voice menus (Interactive Voice Response IVR systems)
• Use speech recognition to also cut through menus– If menus are too long, users get frustrated– Cheaper than hiring 24 hr/day reps
• Voice mail systems– Interface isn’t the best
• Get email in your car– Also helps with non-tech savvy like the elderly
• Potentially aides with– Learning (engage more senses)– Cognitive load (hypothesize each sense has a limited ‘bandwidth’)
• Think ER, or fighter jets
Speech Generation
• Play back speech (games)• Combine text (navigation systems)• Careful evaluation!– Speech isn’t always great
• Door is ajar – now just a tone• Use flash• Supermarket scanners
– Often times a simple tone is better– Why? Cognitive load
• Thus cockpits and control rooms need speech• Competes w/ human-human communication
Speech Generation• Ex: Text-to-Speech (TTS)• Latest TTS uses multiple syllabi to make generated speech sound better
– Robotic speech could be desirable to get attention– All depends on app– Thus don’t assume one way is the best, you should user test
• Apps: TTS for blind, JAWS• Web-based voice apps: VoiceXML and SALT (tagged web pages).
– Good for disabled, and also for mobile devices• Use if
– Message is short– Requires dynamic responses– Events in time
• Good when visual displays aren’t that useful. When?– Bad lighting, vibrations (say liftoff)
Non-speech Auditory Interface• Audio tones that provide information• Major Research Area– Sonification – converting information into audio– Audiolization– Auditory Interfaces
• Browsers produced a click when you clicked on a link– Increases confidence– Can do tasks without visual cognitive load– Helps figure out when things are wrong– Greatly helps visually impaired
Non-speech Auditory Interface• Terms:
– Auditory icons – familiar sounds (record real world sound and play it in your app)
– Earcons – new learned sounds (door ajar)
• Role in video games is huge– Emotions, Tension, set mood
• To create 3D sound– Need to do more than stereo– Take into account Head-related
transfer function (HRTF)• Ear and head shape
• New musical instruments– Theremin
• New ways to arrange music
Displays• Primary Source of feedback• Properties:
– Physical Dimension– Resolution– Color Depth and correctness– Brightness, contrast, glare– Power– Refresh rate– Cost– Reliability– # of users
Display Technology
• Monochrome displays (single color)– Low cost– Greater intensity range (medical)
• Color– Raster Scan CRT– LCD – thin, bright– Plasma – very bright, thin– LED – large public displays– Electronic Ink – new product w/
tiny capsules of negative black particles and positive white
– Braille – refreshable cells with dots that rise up
Large Displays• Wall displays– Informational
• Control rooms, military, flight control rooms, emergency response
• Provides– System overview – Increases situational awareness– Effective team review
• Old: Array of CRTs– Interactive
• Require new interaction methods (freehand sketch, PDAs)
• Local and remote collaboration• Art, engineering
Large Displays
• Multiple Desktop Displays– Multiple CRTs or Flat panels for large
desktops– Cheap– Familiar– Spatial divide up tasks– Comparison tasks are easier– Too much info?
• HMD• Eventually -> Every surface a pixel
Mobile device displays• Applications
– Personal• Reprogrammable picture
frames– Digital family portrait
(GaTech)– Business
• PDAs, cellphones– Medical
• Monitor patients– Research: Modality Translation
Services (Trace Center – University of Wisconsin)• As you move about it auto
converts data, info, etc. for you
Mobile device displays
• Actions on mobile devices– Monitor information and alert
(calendar)– Gather then spread out
information (phone)– Participate in groups and relate
to individual (networked devices)
– Locate services and identify objects (GPS car system)
– Capture and then share info (phone)
Mobile device displays• Guidelines for design
– Bergman ’00, Weiss, ’02– Industry led research and design case studies
(Lindholm ’03)– Typically short in time usage (except handheld
games)– Optimize for repetitive tasks (rank functions by
frequency)– Research: new ways to organize large amounts of
info on a small screen– Study: Rapid Serial Visual Presentation (RSVP)
presents text at a constant speed (33% improvement Oquist ’03)
– Searching and web browsing still very poor performance
– Promising: Hierarchical representation (show full document and allow user to select where to zoom into)
Animation, Image, and Video• Content quality has also greatly
increased• 3D rendering is near life-like• Digital Photography is common• Scanned documents• Video compression • Multimedia considerations for the
disabled• Printers
– 3D Printers create custom objects from 3D models