III ANUAL ARIADNE CONFERENCE, 2003, Leuven. Katholieke Universiteit Leuven, Belgium, 2003.

AdaptWeb: an Adaptive Web-based Courseware

José Palazzo Moreira de Oliveira, Lydia Silva Muñoz, Veronice de Freitas,
Viviane P. Marçal, Isabela Gasparini, Marília Abrahão Amaral

Instituto de Informática – Universidade Federal do Rio Grande do Sul
UFRGS-PPGC

Caixa Postal 15.064 – 91.501-970 – Porto Alegre – RS – Brazil

palazzo@inf.ufrgs.br
http://www.inf.ufrgs.br/~palazzo

Abstract. This paper describes a current project intended to present an adaptive content associated to a specific course and to a particular student profile. Hypermedia teaching applications may use additional learning procedures as guided navigation, hierarchical contents presentation, sequenced deterministic presentations, and other deterministic procedures. On the other hand, different students have different presentation preferences. This paper presents an adaptive environment application for Web-based learning, used in a Numerical Methods course. This course is offered in three different programs: Mathematics, Engineering, and Computer Science. In each program, the complexity (e.g.: theorem demonstration or theorem presentation only), content sequence, examples, and supplementary material of the same course present differences. An approach to implement a computational environment that supports such a need is to organize the educational content into fine grain units enabling their reuse across different scenarios. We are including ontology as metadata representation. Authoring software for syllabus generation is provided, and a run-time environment adapts this content, according to the student program and preferences.

1 Introduction

The importance of the World Wide Web in educational training is unquestionable today. There is a strong need for adaptive courseware to provide educational content that fits to the participant’s cognitive learning style and previous background knowledge. In this paper, we focus on a special application for Adaptive Web-based courses. In this context, students’ preferences about learning contents, navigation resources, and interfaces are evaluated. For that purpose, we consider the application of a Numerical Methods discipline, which is included in three different programs, with differences in each specific syllabus. According to the student’s enrolled program (Mathematics, Engineering or Computer Science), and preferences, different contents of the same course are presented.

Most of the available Web teaching systems applies the traditional paper-based learning resources, making no use of the new resources available on the Web. Among the misused resources, adaptation is a key feature for customized teaching using the Web. Many researchers have addressed the adaptive learning supported by student’s profiles [Rousseau 1999, Brusilovsky 1988, 1999]. In the AdaptWeb research project, a unique syllabus may be adapted to different programs and to different student’s characteristics. The student’s preferences identification process is not trivial. The number and diversity of students require adaptive techniques to fulfill the specific information required in Web-based programs. Another requirement is the learner’s Cognitive Learning Style (CLS) identification and a profound study on how the CLS actually influences his/her cognitive behavior while performing a hypermedia distance Web course [Souto 2002].

In this project, the adaptation is supported by the creation of a student profile, where information about the student’s background, objectives, hyperspace experience, and learning log files are stored and continuously updated. The AdaptWeb System is divided into an authoring environment and a run-time environment module. The authoring environment component helps the author to develop multiple presentation contents for a course, with alternatives for different programs and learning styles. The course creation process is based on the creation of a hierarchy of component topics. The run-time environment provides the course sequence of contents according to the student’s program and characteristics. The AdaptWeb environment is developed in PHP and MySQL.

A mean to achieve this adaptability is to have the educational content organized in fine grain units enabling their reuse among different scenarios. Ontologies are becoming broadly used where machine-readable metadata explaining structured content is needed. This description is a formal specification of domain knowledge enabling the sharing of explicit agreements among human and automatic agents. As part of this work is presented an ontology used in providing metadata to facilitate the reutilization of educational content units for different courses, presentation styles and student profiles in the AdaptWeb Adaptive Web Training Environment. This project is a cooperative action of Federal University of Rio Grande do Sul (UFRGS), and Londrina State University (UEL) supported by grants 68.0194/01-0 and 40.0196/99-9 from Brazilian Research Council - CNPq.

Section 2 of this paper gives an overview of the AdaptWeb environment, section 3 describes the Authoring environment, section 4 presents a brief introduction to AdaptWeb Content Ontology, and section 5 offers a short conclusion.

2 The AdaptWeb Environment

AdaptWeb (Adaptive Web-based learning Environment) [Freitas 2002] is an adaptive Web-based learning hypermedia prototype whose purpose is to adapt the content, the presentation, and the navigation in an asynchronous educational environment according to the student profile. An operational demo of all the operating modes is available at http://adaptweb.homelinux.org.

The AdaptWeb environment, whose architecture is depicted in figure 1, has five main modules: Authoring, Storage, Technological Environment Definition, Adaptive Content Selection and Adaptive Presentation. The Authoring Module defines a methodology to create educational content organized in a structured style and supports the authoring process with an editing tool. With this module, it is possible to correlate the educational units of each discipline to various course profiles of different focus, e.g., engineering or mathematics courses about the same discipline. Each educational unit may require exercises, examples and complementary material. The Storage Module takes the structured content given by the authoring module and stores it in XML and HTML files while the metadata explaining this content is stored in the AdaptWeb Content Ontology. A student model containing the student’s preferences and cognitive learning style is constructed by studying this behavior during the learning practice. Also, while a course is being taken, the student’s technological environment is identified and set by the system into the student model, i.e. the capacity of the student’s technological environment to process different media formats.

The adaptive content selection is made by using the student’s background, the navigational preferences and the cognitive style, which are included in the student model and also by using the existing metadata describing what structure and characteristics the educational units have. Once selected, the structured XML and HTML content are presented according to the student navigational preferences and technological environment.

3 Authoring environment: adaptive syllabus creation

In the AdaptWeb environment, the authoring component allows the author to include different contents in a same topic, according to different programs and different students’ profiles.

The authoring process is composed of the following stages: (1) specification of the course purpose; (2) specification of the course contents outline; (3) specification of contents structure, components, and visualization; (4) classification of contents as foundation topics, examples, additional examples, exercises and complementary material (pictures, movies, simulations, and links to additional information). Also, the complexity level of exercises and examples are stated, as easy, medium, or complex. This classification is used to define the presentation sequence; (5) specification of course contents, according to each program: at this step, programs are associated with topics.

The AdaptWeb environment uses the Extensible Markup Language (XML) for data storage. The possibility of tags definition, Documents Type Definition (DTD) and customized style sheets creation for each application [Bray 1998] supported the XML selection for data storage. In the present project, the Numerical Methods course was selected and adapted to three different programs: Engineering, Mathematics and Computer Science. For each program, a different XML file is created, including the specific program course topics and information about the topics presentation sequence. A XML file is also created for each course topic. A DTD have been developed, and implemented a XML parser, for the XML files validation, in compliance with the Document Object Model (DOM) specification [DOM 1998].

The run-time environment includes the student profile generation and maintenance, and the adaptive presentation of contents. The educational content must be dynamically adapted, according to the students’ evolution model. This model represents the current relationship between the student and the course, and how much the student knows about each application domain topic. The AdaptWeb considers three aspects as relevant for the adaptation process: the student’s current knowledge, the student’s program, and the student’s navigation preferences. The adaptability techniques are supported by information stored in the student model.

Each student model is created in the first AdaptWeb login. Information about enrolled program and courses, as well as general student’s information, should be provided at this moment. Information about the student’s performance is captured from student’s monitoring.

At each login, the student must select one navigational option:

1. Tutorial: contents are accessed according to a previously established sequence. Therefore, for each new section, the presentation should be adapted to previously accessed course components.

2. Free: in this option, every course component is available and users may navigate through the course contents without any restrictions.

The general environment interface has built-in strategies that help the student to navigate in the hyperspace, such as direct guidance (that suggests the best link to proceed), and global maps. The interface presentation of component pages is dependent of the navigation choice. For the free navigation option, all topics are available, and students may use a search tool by keywords, provided for global orientation support. In the tutorial navigation option, students are guided by the use of global conduction technique.

Some adaptive hypermedia techniques proposed by De Bra [De Bra 1999, 2000] are also used in the AdaptWeb. The selected techniques are: link disabling, used for navigation sequence enforcement; links annotation, to identify disabled topics, topics already visited and topics not visited yet; history list, to place the student in the study environment; link removal, to adapt the links according to the program (Computer Science, Mathematics, and Engineering).

4 AdaptWeb Content Ontology

Ontologies were defined by Tom Gruber [Gruber 1993] as “a formal, explicit specification of a shared conceptualization”. Ontologies can be used as metadata explaining resources to be shared among human and automatic agents. In addition, ontologies that will be used by Web agents need to have precise element definitions anchored on the Web, for example by the namespaces mechanism of XML, and representation languages founded in broadly used Web technologies to facilitate their use and take advantage of existing tools. We are presently extending the AdaptWeb to allow an ontological description of the contents (here presented), of the student model, and of the presentation tactics associated with each cognitive style. In the Content Ontology, all educational resource used in the system is considered an element of the LearningObject class, and is described by the properties showed in table 1.

Table 1. Properties describing Learning Objects in the AdaptWeb Content Ontology

Property	Description
description	Description of the content of the Learning Object
keywords	Keywords describing the subjects existing in the Learning Object
location	URI indicating where the Learning Object is
creator	Indicates the creator of the Learning Object

Figure 2 shows the structure of classes and relations in the ontology. The minimal unit of self-explainable learning content in the AdaptWeb environment is called Topic. A topic is the explanation of some concept or idea eventually accompanied with examples, exercises and complementary material to support that explanation. Additionally, a topic may have sub-topics giving more specific and detailed explanations related by the isPartOf relation, i.e. they are considered part of the explanation of the prime topic. All the educational content is grouped in knowledge areas called Disciplines and Customizations of disciplines content for different focus called Courses. In the AdaptWeb ontology, topics are grouped in the class Topic. Additional educational content supporting the theoretical explanation of each topic is in the Support class, which in turn has three sub classes: Exercise, Example and Complementary. Disciplines and Courses are represented in classes Discipline and Course respectively.

Figure 2. AdaptWeb Content Ontology

Courses represent the collection of educational units related to a specific focus over a discipline, for example the discipline Numerical Methods can be focused on Mathematics or on Engineering with some differences in the content, or can be focused on bachelor students or on technical ones.

Individuals of class Topic are available to a Course if they are considered adequate to be part of the theoretical explanation of the course according to the course focus. Individuals of class Support are available to the course content only if they are considered adequate to the course focus even though the supported topic is available to the given course. A prerequisite relation is also defined to represent the necessity for a student to have taken all topics being a prerequisite of a given one.

A taxonomy groups exercises, examples and complementary material in classes that are subclasses of the class Support. Paying attention to the different focus of each course over a discipline, the exercises, examples and complementary material are related by the availableTo relation to the courses indicating if this material is adequate, i.e. available to the focus of the course. The networkConnection relation indicates the minimum speed needed for the network connection of the student session to correctly use the Learning Object. The complexity relation indicates the degree of complexity the Learning Object presents to the typical student. Table 1 indicates the principal restrictions of each defined relation. For example, it is shown that the prerequisite relation can only be used between individuals of class Topic and it holds the transitive property.

Table 2. Relations in the AdaptWeb Content Ontology

Relation	General Restriction	Domain Restriction	Range Restriction
customize	functional	Course	Discipline
isPartOf	transitive	Topic
isAvailableTo			Course
prerequisite	transitive	Topic	Topic
learningPath		Topic	Topic
supportsTo		Support	Topic
complexity			Complexity
networkConnection			NetworkConnection
subClassOf	transitive

The ontology model of the Content Ontology was represented in DAML+OIL [Connolly 2001], and the ontology instances in RDF Schema notation [Brickley 1999]. The code below shows part of the ontology indicating that exercise ExerciseGauss-Seidel is provided for the Numerical MethodsMaths course but not for the NumericalMethodsEngineering course of the same discipline (assuming that it is not stated in another part of the ontology).

<daml:Class rdf:ID=”Discipline”>

<daml:Class rdf:ID=”Course”>

<daml:Class rdf:ID=”Topic”>

<daml:Class rdf:ID=”Support”>

<daml:Class rdf:ID=”Exercise”>

<rdfs:subClassOf rdf:resource="#Support"/>

<daml:ObjectProperty rdf:ID=”isAvailableTo”>

<rdfs:range rdf:resource=”#Course”/>

</daml:ObjectProperty>

…

<rdf:Description rdf:ID=”NumericalMethods”>

<rdf:type rdf:resource= “#Discipline”/>

</rdf:Description>

<rdf:Description rdf:ID=”NumericalMethodsEngineering”>

<rdf:type rdf:resource= “#Course”/>

</rdf:Description>

<rdf:Description rdf:ID=”NumericalMethodsMaths”>

<rdf:type rdf:resource= “#Course”/>

</rdf:Description>

<rdf:Description rdf:ID=”ExerciseGauss-Seidel”>

<rdf:type rdf:resource= “#Exercise”/>

</rdf:Description>

The AdaptWeb Content Ontology instances representing metadata about learning objects in the system are automatically created by a wrapper being executed each time new educational content is generated. The wrapper scrabble in the XML files being aware of the structure and semantics of their content and generates the metadata as RDF descriptions in the ontology. Authors can enrich the ontology by editing it, so they are allowed to create new links and correlate educational units with additional educational material that are external to the set of AdaptWeb educational contents by giving their location and basic metadata.

5 Conclusions

This paper describes an in progress project for adaptive content presentation of Web-based courses, according to selected programs and student’s profile. The proposed solution is demonstrated with the application of the AdaptWeb in the development of the Numerical Computation course, where specifics and different contents of the same course are presented for students from three different programs (Mathematics, Engineering, or Computer Science). In the adaptive environment provided by the system, course contents are customized with different information complexity, sequence of contents access, example application, and supplementary material access. Authoring software is provided for syllabus generation, supported by XML standard files. The AdaptWeb also provides support for student’s monitoring. As a result, the course contents are adapted and presented to students, according to each student’s program, current knowledge, and navigation preferences. Additionally an ontology is being included to support the educational content administration allowing learning object reuse across different scenarios.

Acknowledgments

The authors would like to acknowledge the support of Mario L. Proença Jr., Maria Angélica C. Brunetto, from Universidade Estadual de Londrina – UEL, and Marcelo S. Pimenta, Cora H. F. Pinto Ribeiro, José Valdeni de Lima from Universidade Federal do Rio Grande do Sul during the project as advisors or co-advisors in the Consociate Master Program developed at UEL.

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