HCI Lecture 14
Special Issues: Ubiquitous computing
Barbara Webb
Key points:
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Making the computer part of the environment
Mobile devices
Implicit input
Ambient output
Continuous interaction
Issues for design and evaluation
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Introduction
Human-computer interaction addresses the relationship between
humans and computers, doing tasks in environments
Task
Human
Computer
Environment
The focus should be on supporting human activities
Ideally, the computer would just be part of the background
environment in which we do the task
This concept has been called invisible, pervasive or ubiquitous
computing (Weiser, 1991)
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Introduction
Computation beyond the workstation or desktop computer
(fixed location, screen, keyboard & pointing device).
Includes:
– Handheld, portable and wearable devices
• Mobile phones, PDAs, digital cameras, sat-navs etc.
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Introduction
Computation beyond the workstation or desktop computer
(fixed location, screen, keyboard & pointing device).
Includes:
– Handheld, portable and wearable devices
• Mobile phones, PDAs, digital cameras, active badges etc.
– Very different scales or styles of output
• Very small and very large displays, distributed, 3-dimensional
• Richer sounds, device actuation, ambient cues
• Augmented vs. virtual reality
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Introduction
Computation beyond the workstation or desktop computer
(fixed location, screen, keyboard & pointing device).
Includes:
– Handheld, portable and wearable devices
• Mobile phones, PDAs, digital cameras, sat-navs etc.
– Very different scales or styles of output
• Very small and very large displays, distributed, 3-dimensional
• Richer sounds, device actuation, ambient cues
• Virtual or augmented reality
– Novel forms of input
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Pen-based, touch based, proximity sensing
Voice operated
Tilt or motion sensing
Implicit input – location, time, context
– Embedded computers in other technologies
• Cars, washing machines, etc.
• Instrumented rooms, buildings, environments
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Introduction
Often these factors interact:
Mobile device
Reduced power
and
functionality
Smaller
interface
Specialised
for certain
functions
Alternative I/O
methods
Task specific
interfaces
Improved
usability!
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Guidelines for Small Devices
Should distinguish mobile (usable while moving) from portable
(movable but need to be stationary to use successfully)
Use(fulness) immediately apparent
Structure interface to task
Short cuts and flexibility
Minimise memory load
Use consistent screen templates
Provide a Back function on every screen
Selection is better than writing
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Small devices and the web
Increasingly common for mobile devices to access the internet
Important constraints:
– Smaller screens show less, so memory load increases
– Have awkward and error prone input methods
– Very wide variety of device specifications (screen size, resolution,
layout, interaction options) compared to standard desktop/laptop
– More connectivity and bandwidth issues
– People are unlikely to try to do all the tasks offered by the full site
using their mobile device
Ideally should always make alternative ‘mobile’ site available,
and make it easy to switch between this and the full site
General principle: being able to do anything tends to make
everything take longer to do.
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Norman’s “The Invisible Computer”
“Personal” computer is “massive, impersonal, abrupt and rude”,
used mostly to do social things and not for computing
A device that does everything will be convenient but will
probably perform worse than specialised devices:
– Swiss army knife vs. kitchen knife, corkscrew, screwdriver, scissors
Also get incremental addition of features, amount of information
stored (disk space), amount available (WWW), so can no longer
make everything visible or discoverable
Norman suggests technology should move towards “information
appliances”, i.e. many items serving specific needs:
– ‘Home financial centre’ in right location with right connections
– Displays providing weather, news, sports (compare to clock)
– ‘Foreview’ mirror in cars for traffic, parking spots
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Norman’s “The Invisible Computer”
“Devices that are easy to use, not only because they will be
inherently simpler, but because they fit the task so well that to
learn the task is to learn the appliance.”
Simplicity and visibility of function paramount
Will require infrastructure to allow seamless information transfer
between devices
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The iPhone
Opposite direction: towards multipurpose device
Sensors: proximity, ambient light, accelerometer (orientation) and
touch screen – several advanced touch features
Loss of physical buttons removes ‘tactile landscape’
See http://www.computerworld.com/ for usability test
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Natural interaction
Much concern in HCI about finding more ‘natural’ forms of input
`Context aware’ computing suggests computers should be able
to recognise implicit inputs:
– E.g. walking into a space should be sufficient to announce your
presence and identity
– More generally, tracking the user’s location to supply them with
relevant information (satnav)
– Alternative forms of identification also have many obvious
applications (with varying requirements for reliability)
– Time is another implicit cue: could exploit to detect interest,
deviation from routine, even identity
General idea is that input is a side-effect of doing the activity
Automated capture as a background technology
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‘Invisible’ interaction
Potential to ‘eliminate’ conscious interaction
– E.g. remove ticket sales by tracking where people went and
charging their accounts
– Verichip implant
– Identify patients in
emergency situtation
– Other uses…?
Replaces interaction programming problems with ethical
problems
– Those without resources to be connected to system are
disenfranchised
– Removes option of anonymous interaction
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Natural interaction
Tangible input devices – manipulate ‘ordinary’ physical object
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Continuous interaction
Obtaining natural interaction may involve collapsing the usual
input/ output distinction
`Continuous interaction’ emphasises the closed loop rather than
stages of action
Goals
Sequence of actions
Ongoing activity
Evaluation
The world
The world
On more extended time scales, includes thinking of HCI in terms
of extended, ongoing activities rather than tasks that have a
clear beginning and end
– Should support interruptions, concurrency etc.
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Design processes for continuous interaction
Importance of ethnography in assessing user
requirements (don’t trust post-hoc rationalisation)
what is
wanted
analysis
Augment task analysis with:
Instantaneous information
requirements: will it be part of
task, users memory, computers
memory, or in environment?
Trigger analysis: does next step
occur immediately, after fixed or
variable delay, or in response to
external event?
design
implement
and deploy
prototype
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Evaluation of ubiquitous computing
Some problems for evaluation
– Hard to measure relevant variables
– Inappropriate to use methodologies that interfere with the normal
process (e.g. co-operative evaluation, lab experiment)
– Need long term analysis
– May be fuzzy usability criteria
Standards and guidelines are developing for mobile devices, but
still lagging for more immersive technologies
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References
Weiser, M. (1991) The computer for the 21st century. Scientific
American, 265/3: 94-104
Norman, D. (1998) The Invisible Computer, MIT Press
Williamson, J. Murray-Smith, R. & Hughes, S. (2007) Shoogle:
Multimodal Excitatory Interfaces on Mobile Devices, CHI 2007
See also:
Dix et. al. sections 18.3, 18.4 chapter 20
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