1. Design and Implementation Issues for Explorative Location-based Applications: The NexusRallye Daniela Nicklas, Nicola Hönle, Michael Moltenbrey, Bernhard Mitschang GeoInfo 2004, 22. November 2004 Universität Stuttgart, Germany Center of Excellence 627: Spatial World Models for Mobile Context-Aware Applications

2. University of Stuttgart Center of Excellence 627 2 Overview Motivation A task-oriented approach Sample application: the NexusRallye Requirements Data Model Context management: the Nexus platform Platform architecture Access patterns Lessons learned

3. University of Stuttgart Center of Excellence 627 3 Campus Universität Stuttgart, Germany Scenario

4. University of Stuttgart Center of Excellence 627 4 A freshmen at the University library CS building cafeteria examination office

5. University of Stuttgart Center of Excellence 627 5 Welcome days for CS freshmen First day: Guided tours experienced students show the campus to the freshmen explain the most important things for "survival" welcome party Second day: the Campus rally morning: freshmen teams get sheets of paper with tasks, e.g.: "How many steps are in the math building from first to eigth level?" "What is the registration number of the examination on databases?" "Who is Fabiola and what is she doing in the students lab?" "Write a short poem on the food offered today in the cafeteria." afternoon: teams return, jury assesses the answers winner team gets prize, another party

6. University of Stuttgart Center of Excellence 627 6 Features of the rally game tasks get the players to move around require location knowledge require communication with people reuse of tasks from last year, add new ones general & specific tasks (university & computer science) possible benefits of electronic version: use of existing information spaces (maps, web sites,...) easy reuse of tasks dependency of tasks case study for location-based applications (research goal)

7. University of Stuttgart Center of Excellence 627 7 A task-oriented approach what types of tasks to support? task question task action task multiple choice free text value... find/goTo task bringTo task... target: specific/general stationary/moving

8. University of Stuttgart Center of Excellence 627 8 Overview Motivation A task-oriented approach Sample application: the NexusRallye Requirements Data Model Context management: the Nexus platform Platform architecture Access patterns Lessons learned

9. University of Stuttgart Center of Excellence 627 9 Requirements for NexusRallye get benefits: use of existing information spaces (maps, web sites,...) easy reuse of tasks dependency of tasks support different types of tasks support different rallies sharing tasks automatic scoring (if applicable), else: sending results to the jury (e-mail) multiplayer game

10. University of Stuttgart Center of Excellence 627 10 Use Case player searches for rallies in her surrounding player (or team of players) signs up for a rally player gets initial tasks dependencies between tasks lead player to (multiple) paths through the rally after solving enough tasks or a time-out occured, the game ends player gets result

11. University of Stuttgart Center of Excellence 627 11 Association of tasks and rallies tasks can have more than one location for different rallies, a task can be relevant at different locations Solution: concept of Virtual Task Container (VTC) a rally consists of VTCs each VTC has a certain visibility area VTC references tasks to that area, which get available for player if she enters it

12. University of Stuttgart Center of Excellence 627 12 Sample Rallye Scenario Campus University of Stuttgart 3 2 4 1 player virtual task container with visibility area rallye area ? ? ? ? ? ? ? ? ? ? task reference

13. University of Stuttgart Center of Excellence 627 13 Tasks can lead to each other Campus University of Stuttgart 3 2 4 1 player virtual task container with visibility area rallye area find Nexus lab ? ? ? ? ? go to cafeteria ? ? ? task reference cafeteria Nexus Lab

14. University of Stuttgart Center of Excellence 627 14 Designing a rally choose tasks: use goTo/bringTo tasks to let users go to certain locations choose tasks more or less connected enable different paths through the rally model VTCs: associate appropriate tasks ensure that players always have "something to do" Easter eggs: VTCs with no prior hint (e.g. moveTo tasks)

15. University of Stuttgart Center of Excellence 627 15 Data Model of NexusRallye Task VTC pos: Point visibility: Polygon references … Action Task Question Task Rallye name: String extent: Polygon Player name: String pos: Point ? takes part contains + library, street, copy machine, cafeteria,... context model

16. University of Stuttgart Center of Excellence 627 16 Overview Motivation A task-oriented approach Sample application: the NexusRallye Requirements Data Model Context management: the Nexus platform Platform architecture Access patterns Lessons learned

17. University of Stuttgart Center of Excellence 627 17 Context Management Context model: map data (buildings, streets, POIs,...) user positions (moving objects) tasks and game related objects (for BringTo-tasks) Access: queries and events Design alternatives: local (on the client) server-side (one specialized server) shared (among several servers) multiplayer game, common model necessary no reuse of existing context data Nexus platform

18. University of Stuttgart Center of Excellence 627 18 The Nexus Vision: Federated World Models sensor data WWW Digital Libraries Federation... Local Context Models Digital Information Spaces Context-aware Applications Global Context Model … Multimodal Navigation Smart Factory Mobile City Guide Nexus Rallye

19. University of Stuttgart Center of Excellence 627 19 Federation The Nexus Platform: Architecture Navigation Service Area Service Register Context Server Hoarding Query Component Context Server register application tier federation tier service tier Event Service GeoCast Application A Application B Federation context models: map data, user positions, tasks,...

20. University of Stuttgart Center of Excellence 627 20 Federation Navigation Service Map Service Query Component Event Service GeoCast The Nexus Platform: Access Patterns Area Service Register Context Server Application A Context Server application tier federation tier service tier Application B Query Component Queries notification Event Service notification register Events Value-added Services Navigation Service MapService GeoCast Federation XML interfaces (over SOAP) simple spatial query language (AWQL) spatial model exchange language (AWML) event registration and notification languages (ERL, ENL) Navigation routes (NRL), Map (MapPL)...

21. University of Stuttgart Center of Excellence 627 21 Federation NexusRallye and Nexus Platform Navigation Service Area Service Register Context Server 3: Moving Objects (Players) Hoarding Query Component Context Server 2: VTCs, Rallye- Objects Context Server 1: Campus Model register application tier federation tier service tier Event Service GeoCast NexusRallye Application B Queries: get rallies, get VTC, get tasks Events: OnEnter VTC area, solved moveTo/bringTo

22. University of Stuttgart Center of Excellence 627 22 Lessons learned NexusRallye: good sample application to prove the openess of the Nexus platform explorative location-based applications: demand actions from the user by tasks assumption: user need time and have to see clear advantage games can do this (advantage: edutainment) still pending: user studies to prove acceptability and learning success

23. University of Stuttgart Center of Excellence 627 23 www.nexus.uni-stuttgart.de Obrigada!