ADAPTIVITY IN 3D VIRTUAL ENVIRONMENTS
FOR MULTI-USERS AND ITS APPLICATION
IN ADULT BASIC EDUCATION
Tassawar Iqbal
Institute of Software Technology and Interactive Systems, Vienna University of Technology, Vienna, Austria
COMSATS, Institute of Information Technology Abbottabad, Abbottabad, Pakistan
Klaus Hammermüller
Talkademy, An Open Learning (OLE) Language School, Vienna, Austria
A Min Tjoa
Institute of Software Technology and Interactive Systems, Vienna University of Technology, Vienna, Austria
Keywords: Three Dimensional (3D) Virtual Environments (VEs), Multi-users Virtual Environments (MUVEs),
Adaptive Systems, Adult Basic Education (ABE), Virtual Learning Environments, e-Learning.
Abstract: e-Learning applications have started to exploit web-based three dimensional (3D) Virtual Environments
(VEs) to augment learning experiences. Moreover adaptive support in these 3D VEs further endow potential
to empower the learner’s experiences and enhance effectiveness of learning process by presenting
personalized content and navigational support. Adaptivity in these 3D VEs however, sets the new
challenges for the researchers. Most of the techniques that are devised for adaptive content presentation and
navigation in 3D spaces are focused on single-user environment. Surprisingly few research efforts have
been yet dispensed for the adaptivity in multi-users VEs, however based on textual VEs. In this paper, we
present an adaptive approach for multi-users in 3D VEs. We customize the Adaptive Web 3D (AWE3D)
architecture to provide the adaptive support in 3D VEs for multi-users. We design an adaptive learning
scenario for Adult Basic Education (ABE) in 3D VE of OpenSim to explain, the proposed methodology.
1 INTRODUCTION
In the present era, e-learning applications have
started to exploit 3D VEs to further augment
learning experiences by providing sense of self-
presence, social-presence, immersive environment,
situated-learning and learning by doing. Educational
institutions use these modern technologies and
present learning scenarios for distance and blended
learning (Molka-Daneilsen, 2009). Adaptive support
in these 3D web-based VEs further empower the
learner’s experiences, enhance effectiveness of
learning process and interface usability (Chittaro and
Ranon, 2007a). Adaptivity in 3D VEs however, sets
the new challenges for the researchers. Most of the
techniques that are devised for adaptive content
presentation and navigation in 2D Web sites are not
applicable to build 3D adaptive Web sites because of
different technical requirements of these 3D VEs
(Chittaro and Ranon, 2007b).
Some research studies have presented the
approaches for personalized content presentation,
navigational support and interaction (Chittaro and
Ranon, 2002a; Nussbaumer et al., 2009; Santos and
Osorio, 2004) in 3D VEs. All of these efforts
however focused on single-user VEs. It is surprising
that few research efforts have been yet dispensed for
the issue of adaptivity in VEs for multi-users
(Dieberger, 1996). These efforts are focused on
textual virtual environments where text is used to
describe an imagined landscape.
213
Iqbal T., Hammermüller K. and Tjoa A..
ADAPTIVITY IN 3D VIRTUAL ENVIRONMENTS FOR MULTI-USERS AND ITS APPLICATION IN ADULT BASIC EDUCATION.
DOI: 10.5220/0003305802130218
In Proceedings of the 3rd International Conference on Computer Supported Education (CSEDU-2011), pages 213-218
ISBN: 978-989-8425-49-2
Copyright
c
2011 SCITEPRESS (Science and Technology Publications, Lda.)
In this paper, we present an adaptive approach
for multi-users in 3D VEs. Secondly we customize
and exploit the Adaptive Web3D (AWE3D)
architecture (Chittaro and Ranon, 2007b) to provide
the adaptivity for multi-users in 3D VE. Finally we
present an adaptive scenario for Adult Basic
Education (ABE) designed in the OpenSim
(OpenSim, 2010) environment to explain how the
customized version of AWE3D architecture is
exploited in education domain.
2 RELATED WORK
Surprisingly, few efforts have been made for
adaptivity in 3D VEs. The focal point of these
studies has been adaptive content presentation and
navigational support in 3D VEs. Santos and Osorio
presented an adaptive VE for distance learning that
performs content insertion and removal in 3D space
and navigational support using intelligent agent
(Santos and Osorio, 2004). Apart from educational
domain, lot of work is witnessed on business side.
Virtual reality interfaces to e-commerce sites are
getting more common (Chittaro and Ranon, 2002b).
These e-commerce 3D environments are further
investigated for adaptive support to facilitate the
shopping experience by providing most relevant
product in stores and navigational support on the
basis of preferences and interests of buyers (Chittaro
and Ranon, 2007b). In 2002, Chittaro and Ranon
proposed a generic architecture for adaptive 3D Web
sites named Adaptive Web 3D (AWE3D) that is
responsible for generating and delivering adaptive
VRML content (Chittaro and Ranon, 2002a). This
client-server AWE3D architecture is exploited for e-
commerce case studies and favorable user’s
responses to the system were observed (Chittaro and
Ranon, 2002a). Furthermore, adaptivity using
competence-based Knowledge Space Theory is
presented by Nussbaumer in 3D space of Second
Life (SL) (Nussbaumer et al., 2009). All these
research studies on adaptivity in 3D VEs are focused
towards single-user environment.
For adaptivity in multi-user environments, an
approach is presented in (Dieberger, 1996).
However this approach is developed for textual VEs
(environments base on imagined landscape where
locations, objects, users and their interactions are
described solely through text instead of metaphors).
This approach exploits the concept of ‘read wears’
to provide adaptive support in multi-user textual VE,
where description of objects is changed in imagined
landscape according to frequency of their usage
(e.g., usage frequency of room exits and posting on
bulletin boards).
3 CHALLENGES
OF ADAPTIVITY IN 3D
SPACES
3D environments are more complex than 2D web
sites due to differences in presentation space,
content presentation, organization, navigational
support and users’ actions (Chittaro and Ranon,
2007b). For these reasons, techniques and tools used
for adaptivity in 2D environments cannot be directly
applied for content presentation and navigation in
3D spaces (Chittaro and Ranon, 2007b).
In 2D spaces, optional-fragments and altering-
fragment techniques are common for content
presentation (Chittaro and Ranon, 2007b), whereas
hyperlinks are used to navigate across web pages
(Hughes, Brusilovsky and Lewis, 2002). For content
presentation in 3D space, same techniques are used
where metaphors instead of text (as in 2D) are
selected and 3D spaces are created; however special
care is required to avoid overlapping of metaphors
(Chittaro and Ranon, 2007b). Whereas for
navigational support in 3D space, intelligent agents
(Chittaro, Ieronutti and Ranon, 2004; Chittaro and
Ranon, 2000) and patterns of interaction from usage
data (Celentano and Pittarelo, 2004) are known
approaches instead of simple hyperlinks (as in 2D
space).
All adaptive efforts in 3D VEs focused on single-
user; unfortunately no application is reported in
literature that considers adaptivity in 3D spaces for
multi-users (Chittaro and Ranon, 2007b). In single-
user 3D environments, it is relatively trivial to
provide personalized content and navigational path
according to the user’s needs because there is no
concept of space sharing. On the contrary, adaptivity
in 3D space for multi-users is a complex job. In
multi-users 3D VEs, as the same 3D space is shared
by more than one user simultaneously, adaptive
content presentation for all users in the same 3D
space raises conflicts (like overlapping of contents)
in content presentation that leads towards new
challenges. Similarly navigational support cannot be
customized for an individual user because other
users are sharing the same 3D space and
demarcation in navigational cues for each individual
user is a difficult job (Chittaro and Ranon, 2007b).
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4 METHODOLOGY
FOR ADAPTIVITY IN 3D
MUVE
In 3D Multi-Users Virtual Environment (MUVE) as
more than one user share the same 3D space and it
causes conflicts in adaptive content presentation, and
navigation as discussed in Section 3. We propose an
approach that reduces the conflicts by optimizing the
best common adaptation strategy, where a group of
users (or learners) able to share a portion of 3D
space, customized according to their preferences. In
order to optimize best common adaption strategy,
we divided the 3D space in multiple zones (called
learning- zones for application of ABE) based on
language, domain, level (Beginner or moderate), and
difficulty level in each beginner or moderate levels.
The Figure 1 describes division strategy of 3D
space, where 3D space is divided into sixteen
different zones. Two centric circles set the difficulty
level in 3D space, the outer one is level one (lower
difficulty level) and inner one is level two (higher
difficulty level). In the circular shaped 3D learning
space, the left half of circle is for English language
and the right half of the circle is for Urdu language.
Similarly the upper half of the circle represents a
domain D1 and the lower half of the circular space
forms domain D2. Two lines at diagonal positions
from the upper left quadrate to the lower right
quadrate and from the upper right quadrate to the
lower left quadrate divides 3D learning space for
alphabet learning (for beginners) and vocabulary
(for moderates) learning with respect to language
domain and difficulty level. Each unit of this 3D
learning space is called Learning-Zone as shown in
the Figure 1. Each learning-Zone consists of stage
setting proposed in the Section 6.
Figure 1: Division Plan of 3D Space.
For adaptivity in 3D space for multi-users, we
propose an algorithm. This algorithm exploits the
proposed enhanced AWE3D architecture. When a
learner logins in the 3D space for learning, the
system reads his/her profile. On client-side Linden
Scripting Language (LSL) script initiate a request
for contents (for each learner when he/she logins)
and forward it to the server-side, where the
Personalization module reads the learner profile and
accordingly formulate a query and determines
through the content ontology, what the learner needs
to learn and forward these results (list of LOs) back
to client-side. The OpenSim content Presenter on
client-side finds whether these LOs already available
in some Learning-Zone, if yes, the adaptive system
teleport the learner to the target Learning-Zone, in
case of no, it creates new Learning-Zone with
desired LOs and teleport the learner to the newly
created Learning-Zone, where personalized contents
are presented to the learners and learners’ profiles
are updated accordingly. However if a learner during
a session learns all LOs and more Learning-Zone are
still unlearned, in this case adaptive request within a
session initiated through LSL, forwarded to server-
side application and in response receives description
of imminent LOs, if these LOs already available in
some Learning-Zone then the leaner is teleported to
that zone otherwise new Learning-Zone is created
with selected LOs and learner is teleported there.
The adaptive system also allows learners to leave the
session anytime, in this case their profiles are
updated by the system and they can logout the
system.
The proposed approach is able to assign names at
run time to the different partitioned spaces
(Learning-Zones) and to select relevant Learning-
Zone according to user profile; however static
division may reduce the performance lags.
The selected 3D VE of OpenSim is capable to
fulfill all the technical requirements to develop the
proposed adaptive system. A region in the OpenSim
version 0.6.3.873 allows 45000 prims (OpenSim,
2010). A prim is short version of primitive, means
3D shape. The proposed method exploits less than
hundred prims in all 16 regions that is much lesser
than allowed limit. This consideration of limited
prims avoids performance lags in selected 3D spae
of OpenSim. The reason for the selection of
OpenSim is its support for 1) content scripting, 2)
editable avatars, 3) available for educational
purposes or easily modifiable, 4) capable to run as
standalone application or as collaborative world, 5)
in-world 3D content creation etc (de Freitas, 2008),
and also the proposed methodology is equally
applicable to other 3D spaces offer the same support.
ADAPTIVITY IN 3D VIRTUAL ENVIRONMENTS FOR MULTI-USERS AND ITS APPLICATION IN ADULT BASIC
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215
5 ENHANCED ADAPTIVE WEB
3D (AWE3D) ARCHITECTURE
The architecture we proposed for adaptivity in 3D
VEs for multi-users is based on the Adaptive Web
3D (AWE3D) (Chittaro and Ranon, 2002a). We
customize and use this AWE3D architecture to
provide adaptive support in 3D VEs for multi-users
(see Figure 2). The customized AWE3D consist of
following eight modules;
Figure 2: Customized AWE3D for multi-users adaptive
Support in 3D VE.
Usage Data Sensing Module - This is a client-
based module and it is responsible to collect data
about the users’ interaction in the OpenSim and
sends the collected data through HTTP protocol to
the server-side. This module uses built-in functions
of Linden Scripting Language (LSL) for sensing the
user’s interaction in the OpenSim. This users’
interaction data includes information about user’s
region in which his/her avatar is teleported, current
position of user’s avatar, walking-status of user’s
avatar, flying-status of user’s avatar, sitting-status of
user’s avatar, away-status, touches to metaphors in
3D space and distance from learning object (LO).
The adaptive system collects this usage data using
sensors designed in LSL. Script for sending this data
is also written in LSL.
Usage Data Recorder Module - This module is
responsible for receiving data sent by the Usage
Data Sensing module from OpenSim and stores it
into the Buffer. It is located on the server-side. For
its implementation, we use PHP scripts to deal with
the usage data sent by client-side. This module
receive HTTP request with POST method from the
client-side sending script and it first stores the data
into a buffer and finally transfers and saves it into
the User Model database.
Buffer - The Buffer is a part of server-side
application and its purpose is to reduce the number
of accesses to relational database. It temporarily
stores all the data into a text file, sent by the Usage
Data Recorder module and when stored data exceeds
the set limit of the buffer, it transfers into the User
Model.
Personalization Module - The Personalization
Module is a core component, located on server-side.
It interacts with three components of the architecture
1) User Model, 2) Content Ontology and 3)
OpenSim Content Presenter. It provides session-
based adaptive support. For personalizing the
contents for the users in 3D space, it first takes the
user’s data and usage data from the User Model,
formulate a SPARQL query from this information
and forward it to the Content Ontology. The
Personalization module receives results against the
query. These results (include text-based description
of LOs) are sent back to the OpenSim Content
Presenter Module, against the HTTP request made
by client-side application. The Personalization
module is written in PHP that integrate ontology
model, mySQL database and SPARQL query
execution.
For adaptive navigation support, the
Personalization module finds the location where
relevant contents for the user are available in the 3D
space and teleport the user to that particular location
in 3D space. This personalized navigational support
also addresses the issue of usability (inadequate user
assistance in 3D space) at the cost of user’s control
in 3D space.
User Model - The User model keeps track of
users’ data and usage data sent to it. We use,
MySQL to develop the User Model database.
Information storage and retrieval in the user model
database is made possible by scripts written in PHP.
OpenSim Content Presenter
- This is a client-
based module receives the responses against HTTP
request from the Personalization module and present
the personalized content to the users in the
OpenSim. The OpenSim Content Presenter is
developed using LSL.
Metaphor Inventory -
The Metaphor Inventory
is located on client-side. It is responsible to store 3D
contents in the OpenSim environment. All the
metaphors required for the complete 3D space are
uploaded beforehand and stored in this inventory.
Content Ontology -
Domain ontology for content
serves as contents’ repository on server-side. This
ontological model defines contents of a course. It
consists of two main classes, Learner and Content.
Learner class provides information about the
learner’s domain (to whom he/she belongs) through
specialized subclass named Domain. Instance of the
subclass Domain of class Learner specifies learner’s
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domain e.g., farming, office-worker, kitchenware
etc. The Content class defines contents and it consist
of four subclasses; Alphabet, Common-Vocabulary,
Numeracy and Domain-Specific-Vocabulary. The
Personalization module exploits this ontology for
contents selection according to the learners’ profiles
through SPARQL query and specified rules provide
results to the Personalization module.
6 AN APPLICATION IN ABE
In this section, we describe the reasons for the
selection of learning scenario for Adult Basic
Education (ABE) and use of 3D spaces. Then brief
introduction of learning scenario is presented and
finally personalization support for contents and
navigation is explained through this scenario.
6.1 Why ABE and Why 3D MUVE?
Due to bad experiences from schooling in past,
adults do not prefer to go to literacy programs
(Eberle and Robinson, 1980). Thus educationist and
technologist are striving to offer technology-based
literacy program to augment learning and to attract
these illiterates to the literacy (Hopey, 1998).
Unfortunately, main theme of most of techno-
literacy solutions is text-based, that is not suitable
for absolute illiterates. According to Visual Literacy,
these text-based learning and communication
applications are not acceptable in the present era of
visual literacy and there is need to provide image
dominant learning environments (Aanstoos, 2003).
For effective learning, Gardner’s theory of Multiple
Intelligences recommends to exploits multiple
intelligences in learning environments (Gardner,
1983). Furthermore, features such as sense of self-
presence, social presence, embodied environment,
learning by doing, situated learning, and
collaborative learning, recommended in learning
theories (Dale, 1969; Koh et al. 2007; Kolb, 1984;
Lave and Wenger, 1990) and considered important
for learning are achievable by exploiting 3D
MUVEs.
6.2 Scenario for ABE in 3D Space
We design learning scenarios in the OpenSim for
ABE. In this 3D learning space each learner is
represented by an avatar (an embodied object of a
learner) that can walk, fly, sit, speak and chat under
the control of learner. The learning scenarios are
intended to educate the illiterate learners (target
users of the proposed environment) and these
scenarios are categorized into 1) linguistic scenario,
2) numeracy scenario and 3) game-based scenario.
This paper focuses on the linguistic learning and
game-based evaluation scenarios in order to validate
the multi-users adaptive support in 3D space using
the customized AWE3D architecture. The proposed
scenario serves for learning and evaluation
simultaneously, where a learner may learn
alphabetic characters and commonly used domain
specific words in 3D space with adaptive support of
content presentation and navigation. These scenarios
offer learning material in two languages English and
Urdu (national language of Pakistan), where
alphabetic characters and words are offered for
learning in each language with different difficulty
levels (level I is easier one and level II is difficult
one). Furthermore selection of these learning
contents (alphabetic character/Word and their
metaphors) depends on the learner’s working
domain (scenarios presents different content for
different domains, for instance, house worker,
farmer etc). In 3D space, a stage setting with five 3D
objects presents the learning contents to the learners
as shown in the Figure 1. The larger object on the
left displays alphabetic character/word (written text)
where as four smaller objects on the right present
metaphors (against the alphabetic character/word on
left object). Out of these four metaphoric answers,
only one is a correct answer. Learner is required to
select one metaphoric answer through mouse click.
The adaptive system evaluates whether the learner’s
response is correct or incorrect and update learner’s
profile accordingly.
6.3 Personalized Content Presentation
and Navigation Support in 3D
Learning Space
User data (both usage and user data of learner)
serves as basis for adaptivity in 3D space. For
adaptive content presentation, we consider four
parameters; these are language, domain, learner’s
level (moderate or beginners), and LO last-learned.
These parameters are used to formulate the query to
find out the forthcoming contents for learning. The
Personalization module formulates this query to
personalize content that is executed on ontology.
The results obtained from this query consist of a list
of forthcoming personalized contents for a group of
learners. These results consist of textual information
that is forwarded to the OpenSim Content Presenter
Module to present 3D content in the space.
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Adaptive navigation support is achieved through
the teleporting facility offered by the proposed
system, where learner’s avatar is teleported at
desired location in the 3D space after the
recommendation of user model.
7 CONCLUSIONS
In this paper, we presented an approach that
describes how adaptivity in 3D VE for multi-users is
realized. A customization in the AWE3D
architecture is proposed to achieve adaptivity in
multi-users VEs. We presented application of
proposed approach in 3D learning scenarios for ABE
designed in 3D VE of OpenSim. Using presented
learning scenarios, we described the implementation
strategy of multi-user adaptivity in 3D spaces.
Future work will focus on investigation of
learners’ behavioral data in collaborative learning
scenarios.
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