Interacting with Context-aware Personal Mobile
Devices
Keith CheverstDistributed Multimedia Research
GroupLancaster [email protected]
A Big Question… What can we do to make mobile
personal devices (more) useful? What do we have now?
PDAs, CE, PocketX, PC companion, Epoch. What is on the horizon?
Realistic wireless connectivity, getting better GSM, GPRS, WAP Phones, Bluetooth.
What about applications? Buying books from Amazon while on the
move?
Future Mobile Applications…
Exploit/utilise what is available… Wireless connectivity
Ability to communicate with other systems Control (Did I close the garage door?) Access to dynamic information
Traffic info for Glasgow, latest bowls results? Personal (wearable?)
Will accompany the user, personalisation of the device
Interests (bowls?), Profile (car driver?) Environment – subject to change (mobile!)
Location (Glasgow?), Time, Weather etc.
Exploit/Adapt to Context! Context-awareness,
(1) Device context, e.g. quality of network connection, screen size, sound capability, available battery power, etc.
Previous work focussed on adapting to network QoS MOST application/platform, Agile applications, Odyssey Information flow between App, Middleware and Network
(2) Environmental context, e.g. weather, time, service availability, traffic hold-ups etc.
(3) Personal context, e.g. the user’s preferences (such as interests) and the user’s knowledge/experience
The GUIDE Project Investigate issues raised of
developing a mobile context-aware system Developed to overcome limitations of
traditional information and navigation tools available to city visitor
Group-based Guides inherently inflexible, fixed start-times durations
etc. Satisfy interests of the majority rather than the
specific interests of individuals Guide books
Can contain out of date information etc.
GUIDE Requirements Requirements Capture Conducted at the TIC
Observing information needs of visitors Semi-structured one-to-one interviews with TIC staff
Four main requirements Flexibility
Enable visitors to explore a city in their own way Present Tailored and Context-sensitive
Information Tailored to visitor’s personal and environmental context
Support for dynamic information changing opening times, weather forecasts etc.
Support for interactive services The booking of accommodation, travel etc.
Communications Infrastructure
Communications Infrastructure Cont…
Number of WaveLan transceivers deployed in strategic positions in Lancaster 802.11 compliant
Shared 10 Mbit per communications Cell Cell diameter approx 200m – but this can be
controlled because there is little penetration of waves through buildings
Currently 6 base stations deployed Communications cells used to…
Provide positioning information to GUIDE units Broadcast dynamic information
The User Interface
The User Interface Cont… Based around browser metaphor
Increasingly familiar tool for information navigation and retrieval
Friendly persona, reason… Novice users and the media equation
Flexibility to use the system in different ways Map Local expert Tour Guide
Using GUIDE as a Guide
GUIDE Information Model Represents various information types
Geographic, hypertext and active components
Implications of Disconnection GUIDE units can loose network
connectivity Certain functionality becomes unavailable
Location Information Messaging Service Ticket Booking Reception of Dynamic Information Access to those parts of the Info Model that are
not currently cached e.g. remote web pages
Mobile Awareness Encourage an appropriate mental
model for understanding the role of connectivity Reduce apparent anomalies in behaviour
that could affect a visitor’s trust of the system
Utilises understanding of the mobile phone Reduced functionality when outside of
communications coverage Bars of connectivity metaphor Awareness rather than intrusive
Solving Location Problems: A GUIDE and Visitor Partnership
Evaluation Ascertain quality of experience Determine the Implications of our
approach Would users trust the system? Granularity of location information? What about the role connectivity?
Expert walkthrough & Field Trial 60 visitors tried the system Usage period between 10 mins and 1 hour
Key Findings …. Visitors accepted the mobile phone analogy Visitors appreciated location-aware navigation Visitors trust of the system was dynamic
Level increased when shown detailed and accurate descriptions e.g. ‘watch the step when leaving the path’
Level decreased when information could not be retrieved or appeared inaccurate/incorrect
Visitors in 10-20 age group revelled in technology Explored twice as many links per minute
48/60 visitors wanted conformation of bookings 45/60 accepted the portable end-system
The Role of Network Connectivity
Important role in GUIDE Propagation of information model Location information Affects system’s behaviour and Human-Device
interaction But…
Trust/reliability of information is an issue Information becoming out-of-date during disconnection
Solutions? Connectivity awareness Partnership between system and the user
The Role of Context Simplification of task specification
e.g. What locations are nearby? Careful of overly constraining the
information available to the visitor Tailoring of information
e.g. You have already visited the castle Triggering the presentation of
information e.g. Castle opening early
Future for GUIDE (1) Supplement communications
infrastructure with micro-cellular system, e.g. bluetooth Communication within buildings Finer granularity of positioning info Reduced power consumption
Extend the range of context-sensitive interactive services for city residents Automatically ordering a taxi Requesting the location of nearest cash point
Future for GUIDE (2) Investigate potential for remote
processing Processor intensive tasks, e.g. calculating
tours Different end-systems
Users personal WAP Phones or PDA Persistence of user’s profile
Constant learning/building of user’s profile Integration with other GUIDE systems
International tours/navigation/information?
Future for GUIDE (3) Further evaluation
Potential social impacts Use within groups
Business models Adaptive presentation (Hypermedia)
e.g. Listing attractions based on proximity Problem of unpredictability ILEX (Intelligent Labelling in an art gallery)
Descriptions based on expertise & previously seen items
Learning/Information retrieval Highlight/reinforce associations
Reinforcing Associations… Information(1)
Lancaster Priory built in 1434 A.D. and the architect was Donald Samson.
Information(2) Lancaster Priory built in 1434 A.D. and
the architect was Donald Samson. Note that this architect also designed the extension to York Cathedral which you visited on 12th January 1998.
Supporting Context-aware Applications…
How can a context-aware application: Obtain context Discover what context information is available
Distributed Context Servers Obtain context through notification or polling
Obtaining/adapting to context has side effects Consider location
Based on querying user Based on reception of location updates Based on GPS Based on DGPS
Supporting Context-aware Applications cont… Service selection depends on
context Conserve power + Disconnected
Use service based on querying user Disconnected
Use service based on GPS Connected
Use service based on last received location update
Supporting Context-aware Applications cont… Will need to define policies for
specifying the objectives for adapting to a given context or combination of contexts e.g conservation of battery power
Need to have system wide arbitration to handle conflicting adaptation policies e.g. one active policy might be to reduce
bandwidth while another active policy could be to reduce processing power
Concluding Remarks Development of mobile context-aware applications
Careful use of metaphors (e.g. feedback) and info constraints based on context
Interaction with mobile device is affected by more than the UI (this is especially true when used for control)
Support for context-aware applications needs to consider: Need for generic/scaleable provision/location of context Availability/applicability of context The potential side affects of react/adapting to a change
of context
Contact Information…
[email protected]://www.comp.lancs.ac.uk/computing/staff/kc.htmlhttp://www.guide.lancs.ac.ukGUIDE Papers:
Developing a Context-aware Electronic Tourist Guide: Some Issues and Experiences (CHI2000)
The Role of Connectivity in Supporting Context-Sensitive Applications (HUC’99)
Architectural Support: Architectural Requirements For The Effective Support Of
Adaptive Mobile Applications