Interacting with Context-aware Personal Mobile Devices Keith Cheverst Distributed Multimedia Research Group Lancaster University [email protected].

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Can contain out of date information etc.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