Yet Another Approach to Support the Design Process of Educational Adaptive Hypermedia ApplicationsSymeon Retalis & Andreas Papasalouros

University of PiraeusDepartment of Technology Education and Digital Systems

retal@unipi.gr

The ELEN project: http://www.tisip.no/E-LEN

The paper in brief … Educational Adaptive Hypermedia Applications (EAHA) are

gaining the focus of the research community as a means of alleviating a number of learners’ problems related to hypermedia. However, the difficulty and complexity of developing such

applications and systems have been identified as possible reasons for the low diffusion of Adaptive Hypermedia in web-based education.

Experience from traditional Software Engineering as well as Hypermedia Engineering suggests that a model-driven design approach is appropriate for developing such complex applications.

This paper presents on a model-driven design/authoring process of EAHA, called CADMOS-D. This process accords to the principles of hypermedia engineering

and its innovation is the use of a formally specified object oriented design model.

A design process according to Hypermedia Engineering

Navigational Schema

EAHA description

Navigational Design

OO architectural model

Design step

Product Architectural design

Templates and pages GUI

Interface Design

Process

Evaluation, qualitative review and revisions

Design

EAHA Design

Why a model driven approach? The design process should be driven by a design model. A Design Model

should meet the following requirements [Koper 2000]: Formalism: its notation system must describe a WbEA and its constituents

in a formal manner Completeness: its notation system must be able to fully describe a WbEA,

including all types of its constituents, the relationships among them and their behavior

Reproducibility: its notation system must describe a WbEA and its constituents in an abstract level so that repeated execution/adoption is possible for specific subject domains

Compatibility: its notation system must fit in with the available standards and specifications (IMS, IEEE LTSC, SCORM, etc.)

Reusability: its notation system must make it possible to identify, isolate, decontextualize, exchange and re-use constituents of a WbEA.

Traceability of the design decisions Automatic synthesis of EAHA from its constituents

CADMOS-D design model

The foci of the model: The structure of the learning activities and the

resources that will be used Interaction of the learner with the application Navigational aspects User interface issues

Utilisation of the Unified Modeling Language (UML) for standardised notation

Think of learning activities to start designing …

Navigational Model

Hypermedia Application description

Navigational Design

Design step

Product Activity design

Interface Design

Process

Evaluation, qualitative review and revisions

Design

Hypermedia Design

Activity Model

Presentation Model

Do not think of resources or nodes

Think of learning activities

The Activity Model defines the learning activities that will happen during the instructional process of a specific subject with their semantic interrelationships. The learning activities (read, solve, study, get informed,

etc.) are applied to the various thematic concepts -topics of the domain.

Each learning activity is related to particular learning objectives, notions and topics to be taught,according to the syllabus.

The hierarchy of activities corresponds to the hierarchy of learning objectives, that the learner has to meet via her/his interaction with an educational application under design.

A Schema of learning activities (1)

The learning activities can be associated with each other with specific interrelationships thus forming a semantic network that provides an abstract representation of the solution of the problem of instruction of a specific topic.

This particular view can be reused per se, thus promoting the reusability of educational applications at an abstract level, apart from navigation and presentation issues.

This way, the proposed method incorporates the principle of separation of concerns and promotes reusability.

The activities are associated with specific learning resources. The resources align with the notion of Learning Object. These

resources are physical, reusable, binary entities, either static fragments of digital content, e.g. hypertext, images, videos, simulations, applets, etc,

A Schema of learning activities (2)

A Schema of learning activities (3)

- Courseware. This is the top-level element in the hierarchy of activities that compose the conceptual view of the application.- Activity. This defines a simple activity which is an atomic one. This activity may contain specific attributes. Predefined attributes are the title and the type of the activity (information, assessment, etc).- CompositeActivity. This element defines a composite activity, which contains others, either atomic or concept, thus forming a hierarchy of activities into the educational application.- Relationship. This refers to the association between two activities, atomic or composite.

Intro_video

Title = Introduction to Fire Safety

url = videos/intro.mpg

mime-type = video/mpeg

<<Resource>>

Pretest_html

<<Resource>>

Introduce to Fire Safety

type = Information

title = "Intoduce to Fire Safety"

<<Activity>>

Pretest

title = "Test prior knowledge on Fire Safety"

grade

<<Activity>>

Fire Safety Tutorial

<<Courseware>>

APW

<<Resource>>BC

<<Resource>>

Water Fire Extinguishers

type = Interaction

ready_to_read

<<Activity>>CO2 Fire Extinghishers

type = Interaction

ready_to_read

<<Activity>>

Types of Fire Extinguishers

<<Composite Activity>>

ABC

<<Resource>>

Dry Chemical Fire Extinguishers

type = Interaction

ready_to_read

<<Activity>>

CADMOS-D: Navigational schema The Navigation Model captures the decisions

about how Concepts, Relationships and Resources of the Activity Model are mapped to actual hypertext elements Pages and Links, and how the conceptual relationships defined in the Conceptual Model are driving the structuring of the learning content.

It consists of 2 (sub)models: The Navigation Structure Model. This model defines the

structure of the EAHA and defines the actual web pages and the resources contained in these pages.

The Navigation Behavior Model. This model defines the runtime behavior of the EAHA in terms of navigation.

CADMOS-D: Navigational Structure model (1)

- Content, which is the top-level container in the hierarchy of an electronic content organization.- Composite Node entities that are used as containers, thus composing the hierarchical structure of learning content. The chapters and subtopics in which an electronic tutorial or book are organized are examples of composite entities.-ContentNodes, which are the actual pages of the learning content. -Access structure elements, namely indexes and guided tours, which are related to Content or Composite components

Techniques ofSampling Analog Signals

Sampling of Analog Signals

Practical Sampling AspectsAnd Sample Reconstruction

Conclusions and Exercises

Introduction to DSP

DSPTutorial<<Content>>

Convolution

CADMOS-D: Navigational Structure model (2)

Sampling of Analog Signals

Name = Present the Sampling Process and the Sampling Theorem

<<CompositeActivity>>

Frequency Spectrum of Discrete Signals

Name = Introduce to the Frequency Spectrum of Discrete SignalsType = Information

<<Activity>>

Frequency Response of Discrete Signals

title = Frequency Response of Discrete Signals

<<Node>>

Practical Sampling Aspects

Name = Introduce to Practical Aspects of SamplingType = Information

<<Activity>>

Sample Reconstruction

Name = Inform about Samples ReconstructionType = Information

<<Activity>>

Practical Sampling Aspects & Sample Reconstruction

title = Practical Sampling Aspects & Sample Reconstruction

<<Node>>

Conclusions

Name = Present ConclusionsType = Information

<<Activity>>

Excercises

Name = Assign ExcercisesType = Assignment

<<Activity>>

Conclusions and Excercises

title = Conclusions and Excercises

<<Node>>

Introduction to Sampling

Name = Introduce to SamplingType = Information

<<Activity>>

Sampling of Analog Signals- Node

title = Sampling of Analog Systems

<<Node>>

The Sampling Theorem

Name = Present a Definition of the Sampling TheoremType = Information

<<Activity>>

Sampling of Sinusoidal Signals- Node

title = Sampling of Sinusiodal Systems

<<Node>>

Sampling of Sinusoidal Signals

Name = Introduce to Waveform SamplingType = Information

<<Activity>>

CADMOS-D: Navigational Behavior model

CADMOS-D: Presentation - user interface design (1) each Node in the Navigation Model and its resources are

associated with a presentation model element. Note that a multitude of navigation elements can be

associated with the same presentation specification, thus promoting uniformity and ease of maintenance of the user interface.

The Presentation Model elements have their counterparts in corresponding web technology specifications elements such as HTML and CSS

DSP Tutorial<<Content>>

pfont-family = Verdana, Arial, Helvetica, sans-seriffont-size = 12px

<<CSS>>

DSP Template<<template>>

CADMOS-D: From the design models to automated generation of coursewareCADMOS-D

UML Model

UML Tool

XMI Description

ResourcesCGA Tool

IMS Manifest Description

XHTML Files

CADMOS-D: From the design models to automated generation of courseware

<imsmanifest version="1.3" identifier="TEST"><organizations default="TOC1">

<organization identifier="TOC1"><title>DSP Courseware</title><item identifier="S.10269" identifierref="S.10269_RES">

<title>Elements of Discrete Systems</title></item><item identifier="S.10271" identifierref="S.10271_RES">

<title>Properties of Discrete Systems</title></item><item identifier="S.10273" identifierref="S.10273_RES">

<title>Sampling of Analog Systems</title></item><item identifier="S.10275" identifierref="S.10275_RES">

<title>Sampling of Sinusiodal Systems</title></item>

<!-- . . .--></organization></organizations>

<resources><resource identifier="S.10269_RES" href="units/intro_1.html">

<title>Elements of Discrete Systems</title></resource><resource identifier="S.10271_RES" href="units/intro_2.html">

<title>Properties of Discrete Systems</title></resource>

<!-- . . . --></resources></imsmanifest>

The IMS content packaging manifest

CADMOS-D: The output– A prototype of AEHA

The SCORM ADL Run-time environment (RTE) v1.3, [http://www.adlnet.org/].

CADMOS’s Advantages This work aspires the bridging of the gap between the conceptual

description and the implementation of web applications. Like approaches such as WebML, WCML, UWE, etc. it maintains

the classical, in hypermedia engineering, discrimination of the design of web applications into structure, navigation and presentation design, and uses XML as the product model for the implementation of actual applications.

The use of XMI and the focus of the current method on the specific domain of education, which sets certain constraints in the structure of applications makes it different from the aforementioned methods.

The current work has also close similarities to [Dolog et al 2004], which also uses the same model representation, XMI, and the same method for application generation, XSLT for adaptive applications. The main difference with this method is the provision for navigation and

presentation issues, which is not covered in that work, and the support for Learning Technology Standards.

Method’s Disadvantages

It does not conform to Simple Sequencing standard as yet.

It supports specific aspects of adaptation. The author can create IMS CPs per learner type These CPs can vary

in the arrangement/structure of learning activities in the resources associated with each learning activity In the navigational structure (and behaviour) and the

association of nodes to learning activities In the presentation styles of the nodes

Future plans

To use it in more evaluation studies. The used is “quite extensive”. More than 100 resources, and it

covers a whole semester course To automatically support the IMS SS as an outcome of the

navigational behavior model To create the v2.0 of the CGE tool, as stand alone

To make a more user friendly interface for the CGE tool incorporating “stencils” for the UML diagrams

To integrate the CGE functionality into IBM Rational Rose To check if CADMOS-D can be the basis for designing AEHA

based on “design patterns”. With prof. Franca Garzotto — Hypermedia Open Center,

Politecnico di Milano — we are creating a set of design patterns for authoring EAHA customised to learners’ styles.

The “Global Learner” patternPattern Name: Global LearnerProblem: address the needs of a global learnerSolution: Content Issues

o Provide “the big picture” about a topico Highlight (i.e., give emphasis to) advanced conceptso Provide information about and relationships to the “context” of a topic - theoretical/conceptual, or related to the everyday experienceo Provide information about and relationships to relevant topics in different courses or disciplineso Include exercises at any level of detail about a topico Include exercises that involve creativity and involve generating alternative solutions that differ from the “standard” ones

Navigation and Interaction Issueso Provide the learner with a wide set of navigation facilities. Use indexes (possibly nested in hierarchies) more than guided tours (see “Index Hypermedia Pattern” (Isakowitz et al. 1995))o Support top-down learning, by allowing learners to start navigation from the “big picture” or the “overview” of a subject to the “steps” or the “details”. o Allow learners to look for advanced concepts and to exercise even when all prerequisite elements are not yet fully explored

Activities Issueso Allow the student to input alternative solutions beside offering the selection among a set of “standard” solutionso Allow student to input comments and criticism

Lay-out Issueso In the different pages, highlight challenging exercises and challenging topics

Conclusion

“building adaptive educational hypermedia applications will always be hard. There is inherently no silver bullet”

[as Brooks (1987) said for software]

A Solution to a Problem in a Context

Solution

Problem Context

Alexander defines a pattern as follows:

".... Each pattern describes a problem which occurs over and over again in our environment, and then describes the core of the solution to that problem, in such a way that you can use this solution a million times over, without ever doing it the same way twice"

[Alexander, C., Ishikawa, S., Silverstein, M., Jacobson, M., Fiksdahl-King, I., & Angel, S. (1977). A Pattern Language. Oxford University Press, New York.]

What is a design pattern?

If you find yourself in CONTEXT

For example EXAMPLE,

with PROBLEM,

entailing FORCES

Then For some REASONS,

apply DESIGN FORM and/or RULE

to construct SOLUTION

leading to NEW CONTEXT and OTHER PATTERNS

Alexandrian form of pattern formation

Visit the web site of the ELEN project and register as an interested person:

http://www.tisip.no/E-LEN

Time for discussion