Design and Implementation Issues for Explorative Location-based Applications: The NexusRallye Daniela Nicklas, Nicola Hönle, Michael Moltenbrey, Bernhard

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

University of StuttgartCenter of Excellence 627

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Overview

Motivation

A task-oriented approach

Sample application: the NexusRallye Requirements

Data Model

Context management: the Nexus platform Platform architecture

Access patterns

Lessons learned


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Campus Universität Stuttgart, Germany

Scenario


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A freshmen at the University

libraryCS building

cafeteria

examinationoffice


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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


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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)


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what types of tasks to support?

task

questiontask

actiontask

multiplechoice free

textvalue

...find/goTo

taskbringTo

task...

target:• specific/general• stationary/moving


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Overview

Motivation



Data Model


Access patterns

Lessons learned


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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


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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


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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


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Sample Rallye Scenario

Campus University of Stuttgart

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1

playervirtual taskcontainer withvisibility area

rallye area

?

?

?

?

?

?

?

?

?

?

task

reference


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Tasks can lead to each other

Campus University of Stuttgart

3

24

1

playervirtual taskcontainer withvisibility area

rallye area

find Nexuslab

?

?

?

?

?

go to cafeteria

?

?

?

task

reference

cafeteria

Nexus Lab


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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)


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Data Model of NexusRallye

Task

VTC

pos: Pointvisibility: Polygon

references…

ActionTask

QuestionTask

Rallye

name: Stringextent: Polygon

Playername: Stringpos: Point

?

takes part

contains

+ library, street,copy machine,cafeteria, ... context model


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Overview

Motivation



Data Model


Access patterns

Lessons learned


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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 existingcontext data

Nexus platform


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The Nexus Vision: Federated World Models

sensordata

WWWDigital Libraries

Federation

...

LocalContextModels

DigitalInformation Spaces

Context-awareApplications

GlobalContext Model

…MultimodalNavigation

SmartFactory

MobileCity Guide

NexusRallye


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Federation

The Nexus Platform: Architecture

NavigationServiceArea

ServiceRegister

ContextServer

HoardingQuery

Component

ContextServer

ContextServer

register

applicationtier

federationtier

servicetier

EventService GeoCast

Application A Application B

Federation Federation

context models: map data,user positions, tasks, ...


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Federation

NavigationService

Map ServiceQuery

Component


The Nexus Platform: Access Patterns

AreaServiceRegister

ContextServer

Application A

ContextServer

ContextServer

applicationtier

federationtier

servicetier

Application B

QueryComponent

Queries

notification

EventService

notificationregister

Events Value-added Services

NavigationService

MapService

GeoCast

Federation 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)...


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Federation

NexusRallye and Nexus Platform

NavigationServiceArea

ServiceRegister

ContextServer 3:

Moving Objects(Players)

HoardingQuery

Component

ContextServer 2:

VTCs, Rallye-Objects

ContextServer 1:CampusModel

register

applicationtier

federationtier

servicetier


NexusRallye Application B

Queries: get rallies,get VTC, get tasks

Events: OnEnter VTC area, solved moveTo/bringTo


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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


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www.nexus.uni-stuttgart.de

Obrigada!

Documents

Design and Implementation Issues for Explorative Location-based Applications: The NexusRallye Daniela Nicklas, Nicola Hönle, Michael Moltenbrey, Bernhard