A Learning Oriented Technological Framework for iDTV

Abstract

This paper proposes an open flexible learning oriented technological framework for interactive digital TV (iDTV). The framework is designed to satisfy the pedagogical requirements and deal with the iDTV capabilities and constraints. The framework includes two main products: the authoring tool, where the course is prepared and the course multimedia player, which is capable of presenting the course in an iDTV environment. The proposed approach has been validated in a simulation and real iDTV set-top box (STB) environment.

Full text

A Learning Oriented Technological Framework for iDTV
Francesco Bellotti1, Stefanos Vrochidis2, Ioannis Tsampoulatidis2, Giancarlo Bo3
and Linda Napoletano4
1DIBE, University of Genoa, Italy
2Informatics and Telematics Institute, Greece
3Giunti Labs, Italy
4DeepBlue Sr, Italy
franz@elios.unige.it, stefanos@iti.gr, itsam@iti.gr, g.bo@giuntilabs.it,
linda.napoletano@gmail.com
Abstract
This paper proposes an open flexible learning
oriented technological framework for interactive
Digital TV (iDTV). The framework is designed to
satisfy the pedagogical requirements and deal with the
iDTV capabilities and constraints. The framework
includes two main products: the authoring tool, where
the course is prepared and the Course Multimedia
Player, which is capable of presenting the course in an
iDTV environment. The proposed approach has been
validated in a simulation and real iDTV Set-Top Box
(STB) environment.
1. Introduction
Since the introduction of ICT, the learning industry
has greatly widened the size of the market and the
number of actors and tools. Within this context,
Research and Development projects need to address
real problems and propose viable solutions and
products. This need is an essential requirement for
developing technologies that can effectively support
learning purposes and lead to the definition of viable
products.
Within this continuing evolving context, interactive
Digital Television (iDTV) offers new possibilities for
learning through the technological enhancement of the
traditional TV medium to create more engaging and
effective learning activities.
The purpose of this paper is to present a learning-
oriented technological framework for iDTV, which is
capable of offering services aimed at increasing the
learning opportunities for the general public, mainly at
home.
In order to implement the complete concept (i.e.
make sample courses run on TV) and make the user
tests, that are expected to provide important feedback
about the usability of the system and its effectiveness,
it was decided to develop a fully functional MHP [1]
prototype. This choice is due to the fact that MHP is
the middleware supported by DVB, which is the
reference choice of the European Union and is largely
compatible with other means, such as IPTV and cable
TV [2]. It is true that DVB is working on new
specifications for terrestrial (even if nothing is public
about possible new middleware). However, it is
expected that at least a certain degree of compatibility
will be preserved. In any case, the proposed services
are based on Java, thus are quite portable themselves.
Moreover, DVB itself highlights that DVB-T (and
thus its MHP middleware), despite some drawbacks
and shortcomings, is still the suggested option for the
analog-to-digital transition period [2]. In this view, this
work proposes an MHP-based reference
implementation in order to test with real users and
publicly demonstrate the proposed platform-
independent format to institutions and investors.
This paper is organized as follows: in section 2 the
pedagogical requirements are presented while in
section 3 the technological framework is described.
The results are discussed in section 4, related work is
presented in section 5 and finally section 6 concludes
the paper.
2. Pedagogical Requirements
The first forms of learning with iDTV have been little
more than modified or enhanced videoconferencing.
Today, iDTV platforms for learning provide a big
amount of audiovisual and educational contents to the

viewer through interactive services and content
personalization.
In defining a t-learning pedagogy we consider a user
(learner) centered design perspective and the analysis
of the features of the medium to reduce the risk of
implementing courses that are technically feasible but
pedagogically inconsistent with medium and its
audience.
The learner centered approach aims at considering
and overcoming two fundamental drawbacks present in
educational practices that instead of being solved by
ICT technologies can be amplified by them:
1. The typical educational approach assumes a
world of independent individuals who
"acquire" knowledge according to universal
principles.
2. The co-construction of knowledge in the
learning process is relegated to pre-established
paths that follow an abstraction-instantiation
loop. Most of teaching is done through
abstraction. The students are completely
excluded from the possibility to produce
institutionalized educational paths, even when
the theory goes that proper understanding is
achieved only by co-construction of
knowledge.
iDTV is considered as the convergence of television
and computer technologies by encompassing three
important features typical of computer-based
technologies [3]:
• Interactivity: The control of the whole activity
and of the elements of a single activity can be
placed into the hands of the potential consumer
[4].
• Personalization: Use of technology and viewer
information, to tailor interactive content to each
individual viewer profile [5].
• Digitization: Technological advancements that
allow better quality of sound and picture [6].
However, TV includes features that differentiate it
from PCs. First of all, TV is usually watched by more
than one person (co-viewing), and usually triggers
social interactions that are very useful for a more
effective experience and interiorization of the contents.
Secondly, the logic of broadcasting to a wide
population enables social mass mechanisms that
typically enhance the impact of the broadcast program.
In defining a t-learning pedagogy it is, thus, crucial to
deal with an active learning model, the constraints
imposed by the actual development of the technology
and the nature of the allowed interactions.
In this context the challenge is to exploit the added
value of providing an interactive learning environment
and the potential of allowing people to access learning
activities and contents directly in their house, at
distance, through media easy to access and simply to
use.
This reflection produces a twofold vision that aims
at balancing learning and teaching strategies:
1. Leave the control to the learner.
2. Guide the learner.
Thus, to draw a pedagogy for t-learning experiences
two dimensions have to be explored and taken into
account as the drivers of the design process:
• the context where learning happens and the
behavior of learners in this environment;
• the specific features of the medium.
The interactivity, audio/video-based experiences,
narrative learning environment and informal
learning/edutainment are the key points that emerged
from this exploration.
3. Technological framework
Based on the above pedagogical requirements, a
technological framework has been designed and built
in order to support an efficient development and
deployment of t-learning applications. Such
applications represent a novel educational iTV format,
that can be applied in a variety of fields in education
and not only.
The general philosophy of the approach involves:
• A linear A/V stream (the traditional TV
program, on which the user has no control)
• Non-linear interactive contents (on which the
user has control)
This schema is realizable through existing TVs,
equipped with STBs, thus reaching a wide share of
population. Although internet connection (even not
broadband) is not required, additional services included
in the system are capable of exploiting it in order to
enhance the user interaction and experience. On the
other hand, non-linear Audio-Visual (A/V) stream
contents would require (at least with present
technologies) broadband connectivity, which is not
supported by the majority of current TVs.
More specifically the framework involves two parts:
the production side where the course is prepared with
the aid of an authoring tool; and the client side where
the course is presented to the viewer with the support
of a course player software. The whole procedure is
illustrated in figure 1.
From a pedagogical point of view, this schema
involves an important role of the author, who defines
the learning space and provides strong guidance by
defining the A/V stream, the scheduling and the
contents, and of the user, who has a certain freedom in
exploring this knowledge space (e.g. deciding whether

to perform an interactive test/quiz/game or not, decide
which branch of the course to follow). For any course’s
implementation, the author can decide the desired level
of freedom/customization (e.g. by preparing contents
for various categories, setting user-performance-based
triggers for more information cards, quizzes, letting a
number of parameters variable for personalization,
etc.).
Figure 1: Technological Framework
The technological framework is based on the idea
that the course consists of resources that can be
presented at runtime by the proper course player
software. Modularity, re-usability, customizability,
flexibility, extensibility, homogeneity are the keywords
of such an approach.
3.1. T-learning Course
A t-learning course is considered to be composed of
two main parts: the static and the dynamic part. The
static includes a set of highly customizable multimedia
educational units, which are called cards, while the
dynamic defines the flow of the course in time by the
different condition-based paths, the synchronization
with the A/V stream and the interactions.
In the static part, each card provides one or more
services, which are author-customized instances of
service templates. Such services include: multimedia
pages and presentations, interactive edutainment
elements and support for ancillary devices. Such items
can be presented at runtime by using specific MHP-
java classes which read the property files that are
created in the authoring tool. This means that several
different instances of the same item can be presented
with the support of the same classes that will read
different property files at runtime. This is very
important for the runtime environment of the STB as
one of the major constraints is the limited bandwidth of
the transmitted applications.
Figure 2: Sample Multimedia page
A multimedia page (Mpage) is the most common
item that could be included in a card. It allows the free
location static assets as titles, pictures, text zones and
also interactive assets as buttons. The property file
supports the customization and the personalization of
the page including text fonts, text boxes size and
location, etc. A sample Mpage including several
interactive components such as: text without border,
animated image, image, text inside rounded border area
is illustrated in figure 2.
Figure 3: Instances of Games
Interactive edutainment elements cover various
categories, such as arcade, adventure, puzzle and
educational games. Quizzes, multiple-choice and

memory games could increase the interest of the
viewer-learner supporting the concept of relaxed-
learning that seems suited to TV. The games that can
be included in a course are based on specific
configurable templates and form an MHP-java class
package, which is used for the runtime presentation. In
figure 3, sample instances of Quiz, Couples, Memory
and Puzzle games are illustrated.
Apart from the aforementioned items that can be
included in a card, other services are also supported by
the course’s structure. Such services include the
exploitation of a potential return channel (i.e. internet
connection) for the on demand delivery of requested
material (e.g. documents, maps, presentations etc.) that
can be sent to the user’s e-mail or fax.
The dynamic part of the course, which represents
the actual flow of the cards (figure 4), is encoded in an
XML script which is called “course script” and it is
interpretable at runtime. This script includes the
following information:
• Declaration and synchronization of the cards
with the underlying iDTV A/V stream (thus
directly enhancing the current TV program)
with time stamp definition.
• Declaration of asynchronous cards which are
accessible at any time during the course.
• Links to the corresponding property files of
each card.
• Declaration of navigation bars, that consist of 4
sets of menus (one per each remote control’s
colored buttons) that provide the user access to
additional functions (e.g. personalization
services, more-in-depth info, helps, etc.).
• Condition-based flow control of the course.
Such conditions are based on the real-time
value of dynamic (e.g. score, status etc) and/or
static personalization variables (e.g. age, sex,
etc), that are tracked and managed by the
system.
• Categorized flow of the course. Different user
categories can be defined by the author either
regarding the difficulty level (e.g hard, easy) or
specifying different approaches according to
the user’s skills and the context of the course
(e.g. history profile, architecture profile, etc).
Both the static and dynamic parts of the course are
realized in a package that contains the card resources
(i.e. property files, multimedia objects) and the course
script. This package is the actual outcome of the
authoring tool and it is presentable in the iDTV by the
Course Multimedia Player (CMP).
Figure 4: Dynamic part of the Course. 3
different user categories are represented.
3.2. The Authoring Tool
The AT is a visual development environment where
the author is supported in the creation educational
courses for iDTV. It consists mainly of two logical
parts which are integrated in a common user interface:
a) The script builder, which is the part for writing the
course script (scheduling of the cards, definition of
alternative course paths) that corresponds to the
dynamic part of the course and b) The card
configurator part for the creation and the configuration
of the instances of the service templates (e.g.
Edutainment Templates) which are included in the
static part of the course. The architecture of the AT is
illustrated in figure 5.
Figure 5: Authoring Tool architecture

The AT provides a clear graphical interface (figure
6, 7) which supports visual composition features as
drag and drop, content previews and object designing.
The tool provides a “WYSIWYG” environment where
authors can focus on the contents and the logic of their
course without having to concern about the internal
structure and the constraints imposed by the XML
script.
The concept of the tool is based on the creation of
Learning Objects in a form of XML script and on the
configuration of existing templates.
A Learning Object (LO) [7] can be defined as both
the basic unit of a learning experience and as a small,
atomic chunk of learning that can be reused in different
context. In other words, the LO structure is actually an
aggregation of items, which grant a customizable and
flexible reuse.
Following this definition, and by adopting the LO
model, it is possible to integrate several multimedia
components and thus create educational material and
content suitable for distribution through an iTV
infrastructure. Thanks to this model, the content author
can manage separately the various components, as well
as the parameters that define their behaviour, and then
generate in a simple way the final LO (course) in the
form of a XML script.
The AT script builder (figure 6), which is dedicated
to the definition of the user categories and the
scheduling of the cards, provides authors with an
intuitive way for defining events lists (temporal or
logical) and consequent actions, with the support of
personalization as well. Timeline bar proved an easy
medium for content authors to use since it is more
comprehensible comparing to event triggered-based
flow charts. The tool handles the definition of all the
supported operations/instructions by using an XSD
schema in a “secure” mode, thus avoiding the risk for
the author to generate invalid XML files.
Figure 6: AT Script Builder
Figure 7: AT Card configurator
The AT card configurator (figure 7), which is
responsible for the configuration of the cards provides
a friendly environment where existing templates can be
customized. These templates include Multimedia pages
with images, buttons and text, multimedia
presentations, delivery broker and edutainment
templates, which can be configured appropriately in
terms of appearance, fonts, score computation
modalities, content etc., as described in a previous sub-
section.
The tool supports two modalities of configuring a
newly instantiated service: full configuration, which
gives the author full access to all the configurable
parameters of the service, and the Style configuration,
where the graphics are pre-defined and the author has
to insert the contents (e.g. questions and answers,
images to be manipulated, graphs, etc.). The first
approach is suitable for high customizable solutions,
but may be time-consuming and addresses mostly to
experienced authors, while the second approach is
more efficient since the author can focus more on
content than appearance while authoring process
becomes more rapid and homogeneity insured.
In terms of compliance of the LO generated by the
authoring tool and the existing - worldwide accepted -
e-learning standards, it can be said that the SCORM
specifications was adopted initially as a reference.
Considering the peculiarities of an IDTV-based
environment with respect to more “traditional” e-
learning platforms, it became clear at a very early stage
how SCORM cannot be used as it is to create t-
learning courses and a more suitable structure has been
conceived as explained in the previous sections. We
can therefore say that the AT produces SCORM-like
courses, without precisely following the official
specification. This of course opens wide space for
further discussions in the e-learning standardization

communities and, most probably, for an extension of
existing specifications.
3.3. Course Multimedia Player
The CMP is the software module running on the
STB which is able to present the course after
processing the course package. It interprets the course
script and subsequently creates the data structure
through which it controls the scheduling of the cards,
manages the interaction with the user and performs the
synchronization with the A/V stream. It is constituted
by a number of modules, including:
1) The Course Script Parser interprets the course
script for the current course and accordingly creates the
runtime data structure to manage the course.
2) The Card Scheduler manages the scheduling of
the cards according to the synchronization rules, the
defined user categories, and the personalization
parameters and conditions.
3) The Personalizer provides two major
personalization services: the first one concerns the
scheduling of the cards, the second one the appearance,
contents and functionalities provided by the Navigation
Bar and the additional services (e.g. Edutainment
Templates, Virtual Teacher, etc,). Personalization
parameters include user features and preferences (also
custom defined by the author for a specific course) and
runtime performance.
4) The Graphical Rendering Manager is responsible
for the graphical interface. The graphical user interface
is composed of the Navigation Bar and the cards. A
card typically contains one or more elements, such as
Mpage and games. The MPage itself is a multimedia
container that includes several components of different
types (text rectangles, colour rectangles, images,
buttons, animated images, sounds, timers) that can be
positioned and configured on the screen as specified by
the author (Fig. 2). The video stream can be shown as
well on a portion of the screen, depending on the
instantiated MPage’s configuration. The Navigation
Bar is displayed as a stripe at the bottom (or top) of the
screen and is controlled by the user through the 4
iDTV remote control’s colour buttons (red, green,
yellow, blue). Each button provides access to a cluster
(menu) of functionalities as personalization settings,
choice of course categories, help and other advanced
services.
4. Results
In order to validate the above framework and
preview the courses that are being developed through
the authoring tool an iDTV simulation environment
was employed. We have selected the MHP analyzer
and simulator from IRT software.
Figure 8: Configuring a Multimedia Page
During these tests it was possible to preview the
static parts of the course independently from each
other, and/or the complete course as a global flow.
Using the proposed authoring tool, six courses have
been produced, dealing with the following topics: basic
business, statistics for the Master in Business
Administration, cultural heritage, mathematics for
elementary schools, computers in a life-long learning
perspective and driving school/road safety. The
subjects of the courses were selected in order to cover
a variety of different areas and address different target
users. These courses have been designed by
pedagogical experts from universities and institutes
from 6 European countries.
Figure 9: Preview in the simulator

As an elementary example, figure 8 shows the
configuration of a card, which includes a multimedia
page. Figure 9 shows the corresponding output in the
simulation environment. In this case an image
background was selected by the author, a text area and
an image area were defined and finally two buttons
were introduced to assist the navigation in the course.
Figure 10: Configuring a RightPlace game
The card in figure 10 was configured by inserting a
RightPlace game. Here, the author has inserted a map
as a background and specified the location on the map
of some points of interest (monuments in this case),
whose representing images have to be put at their right
place on the map by the player at runtime (Figure 11).
Figure 11: preview in the simulator
Figure 12 shows a snapshot from an interactive
enhancement of the classic Disney Snow White movie.
This is an example of a post-production enhancement,
which limits the freedom of the iDTV designer since
the interactive part has to be superimposed to a
material that has already been produced and optimized
as a stand-alone product. This requires that the
interactive enhancements be carefully designed and
inserted so to meaningfully enhance the already
defined pace of the movie, without compromising its
quality and features.
Figure 12: a synchronous quiz in the Snow
White enhancement
5. Related Work
Although the research and development in iDTV-
based t-learning is rather limited up to date, some
interesting approaches have been presented.
An interesting approach was the technological
framework for TV supported collaborative learning
proposed in [8]. In this approach t-learning contents are
created with appropriate tools and delivered however
personalization was not applied and the fully automatic
creation of the course was not supported. In a more
recent work [9] a more general framework is presented
with content creation based on XML structures and
templates. Although this work has been an interesting
basis it is still inadequate to deal with learning oriented
content as it serves more general purposes.
Furthermore the two aforementioned approaches
haven’t been tested thoroughly in iDTV or simulation
environment, as no specific results are presented.
Considering the market approach, nowadays there
are considerable tools available, both open source and
commercial, like Composer [10] and Grins Pro Editor
[11]. More specifically, the former is capable of
creating content in NCL [12] language for Ginga
middleware while the latter is a SMIL [13] editor. Such
tools could have been used for the creation of
pedagogical content due to their flexibility, however,

as they are not education-oriented, they would fail to
satisfy the needs of pedagogues.
6. Conclusions
The purpose of this work is to explore how to
enhance learning through interactive TV. The iDTV
technology scenario (which includes modulation,
coding, transmission medium, application middleware,
etc.) is still fluid. And the landscape is complex,
involving a variety of actors such industries, users and
politics.
The presented approach to iDTV is evolutionary,
rather than revolutionary. That is, it still considers the
TV program as a linear AV stream that may be
enhanced through simple interactivity. This is due to
the still high popularity and pervasiveness of the TV as
medium for supplying relaxed/informal information
and stories. We still exploit the “authoritative” role of
TV: a “story” is told (e.g. a documentary), knowledge
is transmitted by an author. Along this path, the user
can exploit interactivity to customize her/his own
knowledge acquisition process by having more-in-
depth information, immediately applying some
concepts in concrete interactive cases, and face
challenges suggested by the author.
One of the results of this approach has been the
development of a set of products, that can be adapted
and applied to several technologies/platforms (IPTV,
cable, sat, etc.). In fact, we have tried to abstract key-
aspects (TV interaction, education, relaxed context of
use) that are independent of the platform, so we have
developed a concept (CMP, AT, Course Script) that
can be used for general linear-stream enhancement.
7. Acknowledgement
This work was supported by the ELU project which
is funded by the 6th FP of the European Union. The
authors would like to thank the coordinator and all the
members of the consortium.
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