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Case Study
Consumer Devices
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Introduction
• 3D Input Device
• Video Recording Devices
• Mobile Communications
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3D Input Devices
• Multiple degrees of freedom– Most devices give you 2 degrees– Usable, but non-natural for 3D applications– We want control of Z axis, and 3 axes of
rotation
• Several different input devices allow this– Data Glove– Spaceball
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History of the Spaceball
• Company founded in the late 1980s, Spaceball Technologies
• Later renamed Spacetec IMC (Interactive Motion Control)
• Later absorbed by Logitech, then spun off as 3DConnexions
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How Does It Work?
• Internal sensors detect displacements / torques along 3 different axes
• Firmware converts into a sream of data, sent to the computer via serial interface
• Data forwarded to "Spaceball aware" applications, which usually convert it into 3D translation / rotation vectors and move something in 3D visual space
• Mappable function keys provide application-specific shortcuts
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Applications
• Mainly industrial CAD designers (automotive, aerospace)
• Creative applications (3D Studio MAX)
• PC Gaming– Hand-held version: SpaceOrb
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How Well Does It Work?
• Very well for CAD / creative apps– Natural mapping to the 3D world– Function keys facilitate bimanual input
• Less well for games, but very subjective
• Not great as a 2D pointing device– Slightly less effective than a joystick
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Video Recording Devices
• As televisions have fairly ubiquitous, time to watch what is shown has often grown less– 200 channels and nothing is on!
• Starting in the 80s, a TV "peripheral" was introduced to solve these problems
• Video Cassette Recorder (VCR)
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Use Model of the Device
• Goal: Record and playback of video
• Task: Record video signals– Subtask: Allow scheduling of recordings
• Task: Playback– Subtask: Searching of recorded "data"
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Artifacts of the Model
• Video Cassette: magnetic recordable media
• Fast Forward and Reverse– Media only supports linear searching
• Start and End of recording times– Lack of updatable data model required end
users to retain lots of domain knowledge to correctly schedule
– No error trapping
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Who Cares About Cassettes?
• The name is now also ubiquitous, but describes the relationship to the media
• What if we recorded onto CD? DVD? Hard disk?– Next generation: Digital Video Recorder
(DVR)• ReplayTV• DirectTV• TiVo ( Jeff says, Best toy EVER!)
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Same Tasks, New Artifacts
• Digital media, and integration of (also ubiquitous) computing technology allows for a whole new interface
• Scheduling of recordings– Start and end times– Updatable database allows reduction of
cognitive load:• Schedule by name ("Record Enterprise") instead of
time• Automatic scheduling ("Record *all* episodes")
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Same Tasks, New Artifacts
• Searching– Fast forward and reverse– Digital format allows variable speeds– Non-linear traversal (jump to end of recording)
• Output to “hard” media– Dump to VCR– Burn DVD– Email!
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Interaction
• User input accomplished using special purpose remote keypad– Up/down/left/right and enter keys– Essentially menu selection and limited form
fillin
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Task: Schedule Recording
• Support recording by selecting times
• Select programs by name
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Task: Playback
• Select program to playback
• Improved searching
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Digital Video Improvements
• TiVo performs all the same tasks as its ancestor, and:– Reduces errors / memory load– Allows improved searching
• Interface appears acceptable to users– Familiar (VCR) style– Menu traversal– Virtual keyboard
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Mobile Communication
• Most common: mobile voice (cell phones)
• Also– Email– IM– Web browsing
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Cell Phones
• Task: Call someone– Subtask: enter the number to dial
• Task: Answer incoming call
• Artifacts: phone
• This is all the early phones had, but new technologies have allowed more features to reduce cognitive load
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Task: Call someone
• Simple task, but lots of conditions– Nature of mobile device means we needs to
know if it's possible to make a call (signal strength)
• Artifact: signal meter
– Household phones have supported speed-dial for years, users expect it
• Artifact: method to setup speed dialing
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Task: Call someone
• Computing technology allows us to store and numbers, reducing the cognitive load– Artifacts:
• setup / retrieve numbers• capture caller ID numbers• capture outgoing calls
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Task: Answer incoming calls
• Simple task, different conditions– Cell phones often used while driving. We want
to reduce potential errors....• Artifact: hands free capability
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Additional 'Tasks'
• Cell phone manufacturers are rushing to combine many other 'tasks' into their phone designs– Buy one device, not several
– Pros: eliminates additional devices, plays to Geek Factor
– Cons: single point of failure, conflicting modalities
• Not a bad thing as long as the primary tasks aren't compromised– Early Palm Pilot phones were had a form factor that
made it cumbersome as an actual phone
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Product: Sanyo Flip-phone
• Task: call someone– Enter numbers directly– Enter/retrieve numbers from phone book
• Shortcut key to phonebook (reduce load, errors)
– Speed dial– Voice dial
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Product: Sanyo Flip-phone
• Task: answer incoming call– One-touch answer– Hands free (requires external device)– Caller ID
• Special rings/graphics per caller, so can easily decide to answer or not
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Product: Sanyo Flip-phone
• Additional tasks:– Voicemail (users require it)– Web browser
• Downloadable content (apps, ringers)
– Text messaging– Camera
• Note: sound of picture being taken can’t be silenced. Why?
– Calculator– Calendar
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Product: Sanyo Flip-phone
• Additional task support:– Menu selection, with shortcuts
• Menu has a ‘Back’ option to repair errors– Early Nokia phones did not have this
– Alphabetic entry via cell number keys• Awkward, but users accept it• Palm Pilot phone does better, but sacrifices form