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Yet Another Approach to Support the Design Process of Educational Adaptive Hypermedia Applications. Symeon Retalis & Andreas Papasalouros University of Piraeus Department of Technology Education and Digital Systems retal@unipi.gr. The ELEN project: http://www.tisip.no/E-LEN.
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Yet Another Approach to Support the Design Process of Educational Adaptive Hypermedia Applications Symeon Retalis & Andreas Papasalouros University of Piraeus Department 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.
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
Do not think of resources or nodes Think of learning activities Think of learning activities to start designing …
A Schema of learning activities (1) • 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 (2) • 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,
<<Courseware>> Fire Safety Tutorial <<Activity>> Introduce to Fire Safety type = Information title = "Intoduce to Fire Safety" <<Activity>> <<Composite Activity>> Pretest Types of Fire Extinguishers title = "Test prior knowledge on Fire Safety" grade <<Activity>> <<Activity>> <<Activity>> <<Resource>> CO2 Fire Extinghishers Dry Chemical Fire Extinguishers Water Fire Extinguishers Intro_video type = Interaction type = Interaction type = Interaction <<Resource>> Title = Introduction to Fire Safety ready_to_read ready_to_read ready_to_read Pretest_html url = videos/intro.mpg mime-type = video/mpeg <<Resource>> <<Resource>> <<Resource>> BC APW ABC 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.
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.
<<Content>> DSPTutorial Introduction to DSP Convolution Techniques of Sampling Analog Signals Sampling of Analog Signals Conclusions and Exercises Practical Sampling Aspects And Sample Reconstruction CADMOS-D: Navigational Structure model (1) • - Content, which is the top-level container in the hierarchy of an electronic content organization. • - Composite Nodeentities 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 structureelements, namely indexes and guided tours, which are related to Content or Composite components
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
CADMOS-D: From the design models to automated generation of courseware
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 ADLRun-timeenvironment (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.
Conclusion “building adaptive educational hypermedia applications will always be hard. There is inherently no silver bullet” [as Brooks (1987) said for software]
Solution Problem Context What is a design pattern? A Solution to a Problem in a Context Alexander defines a pattern as follows: ".... Each pattern describes a problem which occurs overand 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 amillion 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.]
Alexandrian form of pattern formation 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
Visit the web site of the ELEN project and register as an interested person: http://www.tisip.no/E-LEN Time for discussion