Interaction Devices - PowerPoint PPT Presentation

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Interaction Devices


Title: Introduction to HCI Author: Benjamin Lok Last modified by: Benjamin Lok Created Date: 5/28/2004 9:45:29 PM Document presentation format: On-screen Show – PowerPoint PPT presentation

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Title: Interaction Devices

Interaction Devices
  • Human Computer Interaction
  • CIS 6930/4930

Interaction Performance
  • 60s vs. Today
  • Performance
  • Hz -gt GHz
  • Memory
  • k -gt GB
  • Storage
  • k -gt TB
  • Input
  • punch cards -gt
  • Keyboards, Pens, tablets, mobile phones, mice,
    cameras, web cams
  • Output
  • 10 character/sec -gt
  • Megapixel displays, HD capture and display, color
    laser, surround sound, force feedback, VR
  • Substantial bandwidth increase!

Interaction Performance
  • Future?
  • Gestural input
  • Two-handed input
  • 3D/6D I/O
  • Others voice, wearable, whole body, eye
    trackers, data gloves, haptics, force feedback
  • Engineering research!
  • Entire companies created around one single
  • Current trend
  • Multimodal (using car navigation via buttons or
  • Helps disabled (esp. those w/ different levels of

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?

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
  • How important is
  • Accuracy
  • Training
  • Keyboard properties that matter
  • Size
  • Adjustability
  • Reduces RSI, better performance and comfort
  • Mobile phone keyboards, blackberry devices, etc.

Keyboard Layouts
  • Frequently used pairs far apart
  • Fewer typewriter jams
  • Electronic approaches dont jam.. why use it?
  • DVOARK (1920s)
  • 150 wpm-gt200 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
  • Whats in the top row?
  • Look at phones (slight faster), then look at
    calculators, keypads
  • Those for disabled
  • Split keyboards
  • KeyBowls orbiTouch
  • Eyetrackers, mice

  • 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
  • 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
  • This is called Fitts 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
  • 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,

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
  • 1600x1600 res with acoustic wave
  • Must be careful about software design for
    selection (land-on strategy).
  • If you dont show a cursor of where you are
    selecting, users get confused
  • User confidence is improved with a good lift-off

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 arent easy or obvious (pick up and
  • 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
  • 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 lt Trackballs Touchpads lt 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
  • Use multimodal approach or customizable cursors
  • Read Vanderheiden 04 for a case study
  • Designers should smooth out trajectories
  • Large targets reduce time and frustration

  • Five fastest places to click on for a
    right-handed user?

  • What affects time?

Fittss Law
  • Paul Fitts (1954) developed a model of human hand
  • 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
  • No, since if Target A is D distance and Target B
    is 2D distance, it doesnt take twice as long
  • What about target size? Not linear there either
  • T a b log2(D/W 1)
  • T mean time
  • 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
  • Ans 300 200 log2(14/2 1) 900 ms
  • Really a slope-intercept model

Fittss Law
  • T a b log2(D/W 1)
  • T mean time
  • a time to start/stop in seconds (empirically
    measured per device)
  • b inherent speed of the device (empirically
    measured per device) time/bit or ms/bit
  • Ex. a 300 ms, b 200 ms/bit, D 14 cm, W 2
  • 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
  • Newer versions taken into account
  • Direction (we are faster horizontally than
  • Device weight
  • Target shape
  • Arm position (resting or midair)
  • 2D and 3D (Zhai 96)

  • T a b log2(D/W 1)

  • T a b log2(D/W 1)

Fittss Law
  • T a b log2(D/W 1)
  • T mean time
  • a time to start/stop in seconds (empirically
    measured per device)
  • b inherent speed of the device (empirically
    measured per device) time/bit or ms/bit
  • First part is device characteristics
  • Second part is target difficulty

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 is a
    good predictor and joins Fitts Law)
  • Decision Making (Hicks Law)

Very Successfully Studied
  • 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. monitormouse
    (virtual borders)
  • Interesting readings
  • http//
  • http//
  • http//

Precision Pointing Movement Time
  • Study Sears and Shneiderman 91
  • Broke down task into gross and fine components
    for small targets
  • Precision Point Mean Time a b log2(D/W1) c
  • 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

  • Quality of an object, or an environment, that
    allows an individual to perform an action.
  • Gibson (77) perceived action possibilities
  • Norman The Design of Everyday Things

Affordance Examples
Affordance Examples
Affordances Matter?
  • When would affordances matter?
  • Languages
  • Emergencies

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 Technologys Phantom
  • Cons limited applications
  • Sound and vibration are easier and can be a good
  • Rumble pack
  • Two-Handed input
  • Different hands have different precision
  • Non-dominant hand selects fill, the other selects

Ubiquitous Computing and Tangible User Interfaces
  • 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
  • Theres the dream
  • Then theres reality
  • Practical apps dont 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
  • Ray Kurzweil (87) first commercial speech
    recognition software
  • 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, review research
  • Audio
  • Audio psychology
  • Digital signal processing

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,
  • Reduce most questions to very distinct answers

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 (gt than hand/eye)
  • Toys are successful (dolls, robots). Accuracy
    isnt as important
  • Feedback is difficult

Continuous Speech Recognition
  • Dictation
  • Error rates and error repair are still poor
  • Higher cognitive load, could lower overall
  • 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
  • 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 isnt 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 isnt 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
  • All depends on app
  • Thus dont 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 arent that useful.
  • 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
  • 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
  • Ear and head shape
  • New musical instruments
  • Theremin
  • New ways to arrange music

  • 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
  • Interactive
  • Require new interaction methods (freehand sketch,
  • 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?
  • Eventually -gt Every surface a pixel

Mobile device displays
  • Personal
  • Reprogrammable picture frames
  • Digital family portrait (GaTech)
  • 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 guidlines
  • Bergman 00, Weiss, 02
  • Industry led research and design case studies
    (Lindholm 03)
  • Typically short in time usage (except handheld
  • Optimize for repetitive tasks (rank functions by
  • 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
  • Promising Hierarchical representation (show full
    document and allow user to select where to zoom

3D Printing
  • Create custom objects from 3D models
  • Create physical models for
  • Design review
  • Construction
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