CONTEXT-AWARENESS

Aus DPWiki - The Design Pattern Wiki

Illustration

GPS is used to get detailed information about the user's environment - in this case her exact position - and to make this information available to applications such as navigation systems.

Context

…you want to design your mobile application to flexibly adapt to the user's needs and behavior - FLEXIBILITY.

Now you want to make the system provide information that matches the requirements a user may have in a special context or environment.

Problem statement

How can your application use contextual or environmental information to enrich the interaction and communication with users and provide them better services?

Problem description with forces

When humans talk with humans, they are able to use implicit situational information, or context, to increase the conversational bandwidth.

This ability to use contextual information does not transfer well to human-computer interaction. Part of the problem is the poor mechanisms for providing input to computers. Another aspect of the problem is that often we don't know what contextual information is relevant, useful, or even how to use it.

However, by improving the computer's access to its context, we can increase the richness of communication in human-computer interaction and make it possible to produce more useful computational services [1].

Examples

Context is becoming increasingly important in handheld and ubiquitous computing, where the user's context often changes rapidly [2].

However, context-awareness is not well understood, and tools and techniques for developing context-aware applications are still in their infancy. It has been realized that there is a pressing need to obtain a better understanding of what context is in order to facilitate the exploitation of context through context-aware applications.

One very simple example of a context-aware application is personalizing information based on the current location. However, even if location is the most commonly used context data, there is much more to context than that. As part of the context we can have temperature, time, orientation, affective state, activity, interests, focus of attention, interest/boredom levels, resources available, people nearby etc. [3].

An overview about previous research work about context awareness is given in Chen and Kotz's survey [4] in 2000, focusing on applications, what context they use, and how contextual information is leveraged.

Another research project concerning context-awareness and location-based services is SAiMotion [5].

The goal of SAiMotion is to develop a fair guide as a location-based service for mobile devices. The technology to enable indoor-localization, and online data-access, as well as its integration in a mobile client is one of the research focuses. On this basis, an application supporting users in the highly dynamic and information-rich environment of a business fair is planned [6].

Solution

Therefore:

Make your system context-aware!

Context-aware applications use context to provide task-relevant information and/or services to a user [7].

Following on from this, three important context-awareness behaviors that an application might exhibit can be identified:

• the presentation of information and services to a user
• the automatic execution of a service
• the tagging of context to information for later retrieval

Tailor the display to show only information that matches these behaviors.

However, ensure the following directives:

• avoid intransparent, uncontrollable adaptations
• indicate contextual adaptations, e.g. as system proposals
• ensure the stability of the user interface
• allow switching off the contextual adaptations

Diagram

A Working Model for Context [3]

References

This is a basic pattern and has no further references in this pattern language.

Literature and Links

1. Tsibidis, G., Arvanitis, T. and Barber, C. (2000): The What, Who, Where, When, Why and How of Context-Awareness. CHI2000 Proposal for Workshop 11; Available online at http://www.cc.gatech.edu/fce/contexttoolkit/pubs/CHI2000-workshop.pdf
2. Pascoe, J., Ryan, N. S. and Morse, D. R. (1999): Issues in developing context-aware computing. Proceedings of the International Symposium on Handheld and Ubiquitous Computing (Karlsruhe, Germany, Sept. 1999), Springer-Verlag, 208-221.
3. Schmidt, A., Beigl, M. and Gellersen, H. (Dec. 1999): There is More to Context than Location. Computers & Graphics, vol. 23, no. 6, pp. 893-902.
4. Chen, G. and Kotz D. (Nov. 2000): A survey of context-aware mobile computing research. Technical Report TR2000-381, Computer Science Department, Dartmouth College, Hanover, New Hampshire.
5. SAiMotion – Situation Awareness in Motion (Bundesministerium für Bildung und Forschung BMBF, Funding-Key 01AK900A); http://www.saimotion.de
6. Hermann, F. and Heidmann, F. (2002): User Requirement Analysis and Interface Conception for a Mobile, Location-Based Fair Guide. Proceedings of Mobile HCI 2002, Lecture Notes in Computer Science, v. 2411, pp.388-392.
7. Dey, A., Abowd, G. and Salber, D. (2000): A Context-Based Infrastructure for Smart Environments. In Proc. of the 2000 Conference on Human Factors in Computing Systems.