Designing for Context: Usability in a
Ubiquitous Environment
Jenna Burrell, Paul Treadwell, Geri K. Gay
Human Computer Interaction Group
Cornell University
Context-Aware Computing
• Ubiquitous Computing
 Mobile & Wireless Computing
• Context-Aware Computing
Computing devices can gather information about
the user’s external physical environment
(location, who’s around, identity, date and time,
activity) and use it to provide the user with
relevant information or actions.
Mobile devices are an ideal testbed because they
are used in a wide variety of environments
(grocery store, outside, bus stops, conference
rooms, etc.).
Previous Research
• Tourist Guides & Navigation Systems
– Disney World [Pascoe, 1997]
– Atlanta [Abowd et a., 1997]
– Exhibits [Sumi et al, 1998]
• Office Awareness Systems
– User Tracking [Xerox Parctab]
• Tagging Systems
– Fieldwork data collection [Pascoe]
– Stick-e notes [Pascoe]
Social Navigation
• “the process of using cues from other people to
help you find information and potentially to
more fully understand what it is you have
found” [Wexelblat, 1998].
• History: users may interact with information and
environments at different times, but computers can
record these interactions for other users to benefit
from later on.
Our Research
• Previous research has focused largely on technical
issues, how to implement context-aware systems, defining
the space, terminology definition, etc.
• Our goal is not only to implement a context-aware system
but to involve users both in the design and evaluation of
such a system.
• Want to look at questions such as:
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What are the usability issues in a changing environment?
What scenarios do users envision for a context-aware system?
How do user’s think about context (specifically location)?
What info do users associate with locations?
Do users benefit from the information other’s associate with that
context?
Early Studies
• Mobile Computing in a Library
– Students and staff used a mobile device prototype to get
information about library resources from any point within the
library.
– Prototype included location-awareness, library catalog, and realtime chat.
• Participatory Design Session
– Group of wireless laptop users were asked, “what if your laptop
could figure out where you were on campus?” brainstormed with
drawing and text on large sheets of paper.
– Ideas: guided tours of campus, event information to increase
awareness and involvement of students, access to information about
artists in a studio art class, tracking users and privacy issues, IM
system with user proximity information.
Tools Built: Semaphore
• Users associate files
and web pages with
locations
• Divided into default
(anyone at that location
can view the
information) and
Personal (viewable
only by user) folders.
Tools Built: Graffiti
• Text notes are attached to
locations.
• Users can create notes and
attach them to any campus
location.
• Users can read notes posted at
their current location.
Tools Built: tracking use
• Logging mechanism
was built into both
applications for
evaluation of use.
– Log when people
checked for notes
– Log notes they wrote
– Log where they were
– Log when and where
they deleted notes
Graffiti: user study
• Graffiti was installed by ~50
undergrads who were part of a
research study and had wireless
laptops
• We posted notes to encourage
students to think about different
ways to use it
– Building info (history, hours,
facilities, services)
– Event info (by building, by user
pop.)
– Class related info (relevant URLs)
– Location related discussions
(dining hall food, movies)
Evaluation:
• notes in the logging
database
• user questionnaire
Graffiti: user study
Notes posted to Graffiti:
– Discussions held during large
lecture (URLs, criticism of
topic, apology for cell phone)
– Request for help (anyone have
the readings? Anyone take
RSOC 101?)
– General chatting ala ICQ/IM
~ “whispering” in class
– General ads for websites,
games, events (some location
specific, some not)
Graffiti: user study
• Conceptual issues:
– Conceptual model problems -- used like e-mail or
ICQ/IM, did not distinguish between Graffiti and these
modes of communication
– Some saw location-sensitivity as a limitation
– Didn’t really know what to say that related to the
location.
– Many didn’t like being limited to the current context
(ignores user’s capacity for planning)
– Confusion about location-awareness feature.
Misunderstandings about where notes were coming
from and going to (need to know context of other
users).
Graffiti: user study
• Social issues:
– Issue of critical mass – not enough content to warrant
using, not enough users
– Did not support synchronous communication which is
the way most students ended up using it
• Other issues:
– Desire for additional context sensing by the device –
specifically: who’s close by, activity sensing (fun vs.
work)
Future Plans
• Other devices
– Handhelds with wireless capabilities
• Other environments
– Museums
– Landscaping
• Other user groups
– Faculty, staff
– Museum visitors & townies
– Campus tourists