1. ISIS Katrinebjerg i n t e r a c t i v e s p a c e s. n e t 1 Frank Allan Hansen, fah@daimi.au.dk Representing Context in Hypermedia Data Models International Workshop on Context in Mobile HCI, September 19, 2005, Salzburg, Austria Frank Allan Hansen Department of Computer Science, University of Aarhus Center for Interactive Spaces, ISIS Katrinebjerg fah@daimi.au.dk

2. ISIS Katrinebjerg i n t e r a c t i v e s p a c e s. n e t 2 Frank Allan Hansen, fah@daimi.au.dk Agenda Introduction –Mobile, context-aware hypermedia –Requirements for frameworks Defining context –What to sense? –Context and context-awareness –Two views on modeling context in hypermedia models The HyCon Framework –Data model –Architecture –Applications Conclusion and questions

3. ISIS Katrinebjerg i n t e r a c t i v e s p a c e s. n e t 3 Frank Allan Hansen, fah@daimi.au.dk Introduction Pervasive computing provide attractive visions of computer power and information ubiquitously available in our surroundings. Part of this vision is today realized through personal, mobile devices: –Laptops, PDAs, and SmartPhones connected to the network –Hypermedia systems on such devices make it possible to both access and produce situated information –For mobile hypermedia systems to be truly useful it is necessary to add context-aware capabilities to aid users in finding and producing relevant information

4. ISIS Katrinebjerg i n t e r a c t i v e s p a c e s. n e t 4 Frank Allan Hansen, fah@daimi.au.dk Context-aware Hypermedia Bluetags RFID Visual Tag ID

5. ISIS Katrinebjerg i n t e r a c t i v e s p a c e s. n e t 5 Frank Allan Hansen, fah@daimi.au.dk Context-aware Hypermedia Requirements Requirements for a context-aware hypermedia framework: –Extensible data model capable of representing object or entities and their context –Hypermedia model integrated in the data model –Services for accessing the data: Object, context, and hypermedia structures –Services should be useable from many different (mobile) devices –Devices should support capturing of sensor data used to measure the context

6. ISIS Katrinebjerg i n t e r a c t i v e s p a c e s. n e t 6 Frank Allan Hansen, fah@daimi.au.dk Context Very overloaded word in computer science –analyzing and designing for specific use contexts, multitasking context switch, context-free languages and grammars, contextual links, context-sensitive help etc. Physical Context – What to Sense? –User actions Motion, tilt, touch –Environment Light / dark, temperature, time IR, RF, bar codes, glyphs Location, proximity –Information about task Link to Brooke's Sensors pageBrooke's Sensors page –magnetic, acceleration, pressure, humidity, tilt, ultrasonic, movement, gas, speech, smell, …

7. ISIS Katrinebjerg i n t e r a c t i v e s p a c e s. n e t 7 Frank Allan Hansen, fah@daimi.au.dk Defining context Dey’s operational definition (2001): –“Context is any information that can be used to characterize the situation of an entity. An entity is a person, place, or object that is considered relevant to the interaction between a user and an application, including the user and applications themselves.” –Can be used to design for context in frameworks

8. ISIS Katrinebjerg i n t e r a c t i v e s p a c e s. n e t 8 Frank Allan Hansen, fah@daimi.au.dk Context-awareness Dey’s definition (2001): –“A system is context-aware if it uses context to provide relevant information and/or services to the user, where relevancy depends on the user’s task.” Dey’s modes of operation (2001): –Presentation of information and services –Automatic execution of services –Tagging of context to information to support later retrieval

9. ISIS Katrinebjerg i n t e r a c t i v e s p a c e s. n e t 9 Frank Allan Hansen, fah@daimi.au.dk Context In Hypermedia Models Context as collections: –Context can be modeled as collections of first class objects in the model. Objects being part of the same collection are considered to belong to the same physical context. This model corresponds to a belongs to relationship where the objects exist in a context.

10. ISIS Katrinebjerg i n t e r a c t i v e s p a c e s. n e t 10 Frank Allan Hansen, fah@daimi.au.dk Context In Hypermedia Models Context as object attributes: –Context can also be modeled by assigning attributes, describing context parameters, to data objects. This allows context to be modeled as simple key-value(s) pairs and corresponds to objects that have a context relationship.

11. ISIS Katrinebjerg i n t e r a c t i v e s p a c e s. n e t 11 fah@daimi.au.dk The HyCon Framework Data model Architecture Applications

12. ISIS Katrinebjerg i n t e r a c t i v e s p a c e s. n e t 12 Frank Allan Hansen, fah@daimi.au.dk HyCon Data model

13. ISIS Katrinebjerg i n t e r a c t i v e s p a c e s. n e t 13 Frank Allan Hansen, fah@daimi.au.dk HyCon Architecture

14. ISIS Katrinebjerg i n t e r a c t i v e s p a c e s. n e t 14 Frank Allan Hansen, fah@daimi.au.dk Prototypes: HyConExplorer HyConExplorer/J2ME HyConExplorer Tablet Ed. Mobile hypermedia system supporting: Browsing Searching Producing annotations and structures

15. ISIS Katrinebjerg i n t e r a c t i v e s p a c e s. n e t 15 Frank Allan Hansen, fah@daimi.au.dk HyCon Applications HyConExplorer HyConBoard Web publishing

16. ISIS Katrinebjerg i n t e r a c t i v e s p a c e s. n e t 16 Frank Allan Hansen, fah@daimi.au.dk Conclusion Data models in pervasive software architectures, requires flexible and extensible designs since they must support the modeling of arbitrary context information. Two ways of modeling context in data models for hypermedia applications and frameworks: –Context as collections of objects corresponding to a belongs to relationship where the objects exists in a context –Context as object attributes corresponding to objects that have a context relationship which can be modeled by key- value(s) pairs. The HyCon framework and data model is a concrete example of these two ways of representing context.

17. ISIS Katrinebjerg i n t e r a c t i v e s p a c e s. n e t 17 Frank Allan Hansen, fah@daimi.au.dk Questions ? For more information about the HyCon framework and HyCon applications please visit: http://www.daimi.au.dk/~fah/hycon/html Thank you!