Yet Another Approach to Support the Design Process of Educational Adaptive Hypermedia Applications...
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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
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