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 ComputingComputing 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:– 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 real-time 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