Carnegie Mellon Universityís SWAP Project Contribution
Students: Tiffany Chang, Asa Sherrill, Gil Tolle, Brandon Weber
Faculty: Fabien L. Gandon, Norman M. Sadeh
objective of this study was to leverage contextual information to support Semantic Web
P2P scenarios. The study was conducted on Carnegie Mellon Univesityís campus, leveragring
the campusís Wireless LAN (WLAN) and the MyCampus Semantic Web environment
developed by the Mobile Commerce Laboratory over the past few years. Within this
environment, users can access a variety of context-aware applications and services from
PDAs over the WLAN. Examples of contextual attributes include user location (acquired
through location tracking functionality running over the WLAN), calendar information, a
variety of preferences (e.g. food preferences, topics of interest), weather information, social
information (e.g. classmates, teachers, etc.). The campus through the rich set of activities it
supports (e.g. shopping at stores, eating at restaurants, attending movies, practicing sports,
socializing, attending classes, etc.) provides a rich microcosm of everyday life that is
representative of many of the challenges involved in successfully deploying mobile Internet
applications. The WLAN, which includes 700 access points, is accessed daily by over 3,000
users and covers the entire campus.
Figure 1. Screenshots
developed and deployed prior to this particular project include a restaurant
concierge agent capable of suggesting places where to eat, taking into account the userís
location, how much time she has before her next class, food preferences, weather, and a
number of other contextual attributes. Another popular agent is a context-aware message
filtering agent that dynamically determines whether and when to display incoming messages
to users, taking into account the nature of the message (identified through semantic
annotations) as well as contextual information about the user (e.g. "when in class, I donít
want to be disrupted by incoming messages"). Over the years, a number of agents have been
developed and evaluated with both computer science and Human Computer Interaction (HCI
students. In the context of SWAP, we developed and evaluated a context-aware virtual poster
application that enables users to publish and discover announcements in a peer-to-peer
fashion, using contextual information and a number of relevant domain ontologies to
selectively identify relevant postings. Contextual information is essentially used here to
provide additional semantics in support of peer-to-peer interactions among students. The
system was developed and evaluated over a period of six month with a team of 4 HCI
students (Tiffany Chang, Asa Sherrill, Gil Tolle, Brandon Weber)
working closely with the MyCampus team led by Dr. Fabien Gandon and Prof.
Norman Sadeh. Figure
1 displays a few screen shots of the InfoBridge application built as part of this project.
InfoBridge allows students to post and retrieve virtual posters, which are annotated with
contextual information (e.g. type of event, time, location, etc.). Contextual information such
as places where a user goes to on a typical day can be used to construct a semantic profile.
The profile can later be used to automatically or semi-automatically retrieve (or even alert)
the user about relevant events.
Figure 2. Contextual information such as places where different users go on campus
during a typical day can be used to construct semantic user profiles, which can later be
used to retrieve relevant posters.
Example of a scenario evaluated with students:
Ann knows about an interesting art gallery showing going on at the Frame Gallery. She walks
by it and through her PDA, attaches a virtual poster to it containing information about the
event (description, location, and time). Jim, who is an art enthusiast, immediately receives the
poster independently of his location. Later, Bobby walks by the art gallery and did not state
any preference concerning art. Since he is close to the gallery, his PDA beeps; he can either
look at it immediately or ignore it for now and review it later with other the posters he
collected while walking around the campus. When he looks at the poster he can add the event
to his calendar if he likes it, discard the poster or even state he does not want to see any other
poster concerning art. Once the date of the art gallery showing passes, the poster is no longer
valid, and thus gets deleted from the system.
Summary of Results:
A detailed report has been written about the system we developed and the results of our
experiments. The study strongly suggests that contextual information can play an important
role in providing additional semantic information in support of P2P scenarios.