1. MIDAS – 10/27/2003 MIDAS Multi-device Integrated Dynamic Activity Spaces Dissertation Proposal by Unmil P. Karadkar CSDL and Department of Computer Science Texas A&M University

2. MIDAS – 10/27/2003 Outline The nature of Web-based services A need for change MIDAS –Architecture –Characteristics –Evaluation Research Contribution Work plan

3. MIDAS – 10/27/2003 Contemporary Web Services HTTP is server-centric –Session management –Information delivery Request-response architecture –Server only responds to the client that requesting client All clients are treated at par –Personalization addresses user characteristics, not those of the client device request response

4. MIDAS – 10/27/2003 Assumptions of Web Services All clients are, more or less, alike –Desktop computers –800 X 600 or 1024 X 768 color displays –At least 56Kbps internet connection –Abundant processing power and storage space Desktop computers –Dominant when HTTP was designed –Located in secure home or office environments

5. MIDAS – 10/27/2003 Attack of the Phones Proliferation of mobile devices –Notebook computers, PDAs, cell phones and pagers Diversity in characteristics of client devices –96 X 96 to 1600 X 1200 pixel color or monochrome displays –Processing and storage space crunch –Connection speeds vary Diversity in characteristics of the environment –Private or secure locations (homes and offices) –Semi-private locations (cars) –Public locations (airports, hotel lobbies, malls)

6. MIDAS – 10/27/2003 Serving mobile and desktop devices Services HTTP Datastore Services WAP Remodeling of existing services –Little consideration for context or environment All mobile devices are treated at par Alerts are specific to a device –What if the device was unavailable?

7. MIDAS – 10/27/2003 Building device communities People typically carry more than one device –Notebook, cell phone, PDA, pagers Different devices have different strengths –Cell phones—audio, PDAs—video, text Integration of these devices –Reduces reliance on any one device (redundancy) –Provides options for delivering information –Help deliver information that none of the devices can render by themselves (co-use)

8. MIDAS – 10/27/2003 Power to the clients Client devices have better knowledge of –Their own capabilities Display, storage, connection –Their location GPS helps pinpoint device location The location can be mapped to a physical spaces Characteristics of physical spaces can be determined –User activity

9. MIDAS – 10/27/2003 MIDAS M ulti-device I ntegrated D ynamic A ctivity S paces

10. MIDAS – 10/27/2003 MIDAS - Architecture Users Hypertext Authoring Tool Hypertext Specification Information Service Device 3 Device 2 Device 1 Browser 4 Browser 3 Browser 2 Authors The WebTrellis and caT Browser 1

11. MIDAS – 10/27/2003 Device 3 Device 2 Device 1 Browser 4 Browser 3 Browser 2 MIDAS - Architecture Authors Users MIDAS Device Manager user and device profiles, current device load resource handles, author preferences user actions Browser 1 Select Device(s) status, user actions Browser Coordinator Browser registry user actions information content Hypertext Authoring Tool Hypertext Specification Information Service resource handles, constraints, preferences information content, resource properties Resource Realizer Resource Repository resource instance(s) resource handle, constraints Resource Author Authors

12. MIDAS – 10/27/2003 MIDAS - Characteristics Will extend the caT system Information service interacts with the virtual device symbolized by the Device Manager The Device Manager decides where and how to render every information element based on –Available devices –User and/or author preferences Every device presents information in a format that it can support Intrinsically supports –Accessibility –Internationalization

13. MIDAS – 10/27/2003 Attributes that affect browsing Device –Display (resolution and colors) –Storage space –Processor speed –Bandwidth User –Expertise –Media, device and other preferences –Access privileges Environment –Privacy –Security –Interference Information elements –Media (mime) type –File size –Version –Creator –Creation timestamp –Location –Textual description –Required display space –Display colors –Required bandwidth –Language –Priority –Privacy

14. MIDAS – 10/27/2003 MIDAS - Issues Authoring strategies for optimal coverage of devices with minimal effort Defining policies –Device Manager—choosing devices –Browser Coordinator—choosing browsers –Resource Realizer—returning the “best possible” resource User Interaction: interfaces to –Indicate their preferred devices for a variety of conditions –Override system choices –Include third party or public access devices in the device space Interaction with the public devices in a user’s space

15. MIDAS – 10/27/2003 MIDAS - Evaluation Evaluation with simulated rather than real devices –Configurable for a wide variety of devices –Will facilitate testing without incurring the expenditure Criteria –Completeness – all information is presented –Validity – each information element satisfies all user and system constraints –Coherence – the individual elements do not conflict with others (simultaneous rendering of audio/video elements on different devices) –Comprehension – the user can understand and use the presented information Other details still being worked out

16. MIDAS – 10/27/2003 MIDAS – Research Contributions An architecture that –Adapts presentation in response to user, device, environment characteristics –Supports dynamic inclusion and exclusion of devices –Uses multiple devices in tandem for the presentation –Facilitates user interaction from any or all devices –Integrates included devices into a single virtual device –Supports opportunistic inclusion of other appliances –Allows authors to specify the elements that must be presented faithfully An operational system that implements this architecture

17. MIDAS – 10/27/2003 MIDAS – Research Contributions Identification of issues in –Information presentation to a set of devices –Simultaneous presentation of multiple audio-video elements –Minimizing authors’ efforts while ensuring that their hypertexts can be rendered on the widest possible range of devices A satisficing resolution of these issues

18. MIDAS – 10/27/2003 MIDAS – Work Plan Modify existing caT server-side components –Include necessary features in xTed and the caT server Design and develop MIDAS components –Device Manager –Browser Coordinator –Resource Realizer (authoring and delivery) Modify caT browsers or develop new browers Design communication protocols between –caT server and Device Manager –Device Manager and Browser Coordinators –Browser Coordinators and Browsers –Browser Coordinators and Resource Realizer

19. MIDAS – 10/27/2003 MIDAS – Work Plan Design policies for –Selecting devices for serving resources –Choosing the optimal data formats for resources –Resolving conflicts between author and user preferences –Inclusion of public-access devices Evaluate MIDAS Write Dissertation

20. MIDAS – 10/27/2003 Questions?

21. MIDAS – 10/27/2003 Related Work SMIL Capability-based information delivery –Digestor and Pythia (1996, 1997) Use of proxy-based customization of Web content Unintended consequences due to automated conversions –WebSplitter (parts of Web pages are delivered to devices) –Power browser (summarizes Web forms for mobile users) Document Specification –Multivalent documents (High processing and network transfer costs) Multi-device information access –MMUI (Multi-Machine User Interfaces) –Windows-specific –Use of PDAs for input and display extension

22. MIDAS – 10/27/2003 Trellis A hypertext system based on colored, timed Petri nets –defines document structure using Petri nets –supports browsing semantics of hypertext documents based on the Petri net state –has a distributed client/server architecture Adaptation of presentation –server side (WWW) –client side (Trellis, caT) –coordinated between the server and clients (MIDAS)

23. MIDAS – 10/27/2003 Trellis hypertext system Based on colored, timed Petri nets Supports –specification of structure and browsing semantics of hypertext documents –Analysis of authored hypertext structures –specification of access control –time-based hypertext browsing Separates –content from structure –presentation from content

24. MIDAS – 10/27/2003 Examples of Petri nets

25. MIDAS – 10/27/2003 caT Incorporates context-awareness in Trellis Provides for basic user modeling Structured tokens contain dynamic and environmentally changing data Transitions may contain conditional statements Hierarchical nets to simplify authoring of large nets