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Human Computer Interaction CIS 6930/4930 Section 4188/4186

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Presentation on theme: "Human Computer Interaction CIS 6930/4930 Section 4188/4186"— Presentation transcript:

1 Human Computer Interaction CIS 6930/4930 Section 4188/4186
Interaction Devices Human Computer Interaction CIS 6930/4930 Section 4188/4186

2 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!

3 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)

4 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?

5 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.

6 Keyboard Layouts QWERTY DVOARK (1920s) ABCDE – style Number pads
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

7 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

8 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

9 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)

10 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

11 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

12 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.

13 Indirect-Control Pointing
Pros: Reduces hand-fatigue Reduces obscuration problems Cons: Increases cognitive load Spatial ability comes more into play Mouse Familiarity Wide availability Low cost Easy to use Accurate 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

14 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

15 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

16 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

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

18 Example What affects time?

19 Fitts’s Law MT = a + b log2(D/W + 1)
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: log2(14/2 + 1) = 900 ms Really a slope-intercept model

20 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: 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)

21 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:

22 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

23 Novel Devices Themes: Foot controls 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’

24 Novel Devices Eye-tracking Multiple degree of freedom devices
Accuracy 1-2 degrees selections are by constant stare for 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

25 Novel Devices Boom Chameleon DataGlove
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

26 Novel Devices Haptic Feedback Two-Handed input
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)

27 Novel Devices Paper/Whiteboards Handheld Devices
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.

28 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

29 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

30 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

31 Discrete-Word Recognition
Individual words spoken by a specific person Command and control 90-98% for 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)

32 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

33 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

34 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 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

35 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

36 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)

37 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

38 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

39 Displays Primary Source of feedback Properties: Physical Dimension
Resolution Color Depth and correctness Brightness, contrast, glare Power Refresh rate Cost Reliability # of users

40 Display Technology Monochrome displays (single color) 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

41 Large Displays Wall displays Informational Interactive
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

42 Large Displays Multiple Desktop Displays HMD
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

43 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

44 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)

45 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)

46 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

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