A framework for the flexible content packaging of learning objects and learning designs.
The key to delivering effective multimedia educational material is the adoption of a multimedia framework embracing the wide range of content required by users and a learning design framework, which will support the aggregation of learning objects with an underlying pedagogical focus. Such a framework will require the capability not only to define a structure for the educational content to be delivered, but also present the content in a functional format that it is useful to the end-user. This functionality must include sufficient flexibility to allow interoperability between different terminals or devices, and provide a dynamic presentation of content to suit each user (for example, instructional designers, instructors, managers, teachers, students, etc.). In addition, the framework should support key criteria such as simple authoring, rights management, reusability, modification, archiving, and searching.
With its focus on interoperability and flexibility (Bormans & Hill, 2002), the emerging MPEG-21 framework is well suited to solve the outlined problem. MPEG-21 also addresses reusability issues as it allows external and internal referencing to sections of the framework. However, in order for the MPEG-21 framework to support retrieval, adaptation, and delivery of learning objects, it must include meaningful pedagogical descriptors in its structure.
This paper proposes a hierarchical learning design framework based on the MPEG-21 standard. This structure permits seamless integration of various learning objects into a hierarchical structure, where each level of the hierarchy may embed unique metadata and rights protection.
While debate continues about the exact nature and definition of learning objects (Hodgins, 2002) and appropriate instructional models for their construction (Longmire, 2000; Boyle, 2003), the attention of some theorists and researchers has turned to the problem of how learning objects can be implemented to create high quality educational experiences (Bannan-Ritland, Dabbagh, & Murphy, 2002). As Wiley (2003) points out, "The simple concatenation or sequencing of decontextualized educational resources does not produce a meaningful context for learning" (p. 2).
The proposed framework presented in this paper, hereafter the Smart Learning Design Framework (SLDF), aims to draw together the concepts of learning objects and learning designs by defining a process that will assist teachers and instructional designers to create high quality learning experiences. For the purposes of the SLDF, we define learning objects as the smallest autonomous pedagogical unit that cannot be broken into smaller sub-units; examples could be lecture slides, quizzes, and audio tracks. A learning design refers to the way in which activities/tasks, content resources, and support mechanisms are planned and sequenced for students. The implementation of a learning design can be referred to as a unit of study (Koper, 2001), which may comprise a single activity, a module, a lesson, or an entire subject/course. The proposed SLDF process includes the following steps:
* Assembling appropriate multimedia resources into learning objects that exhibit a transparent data format and facilitate storage, adaptation, and reuse (i.e., use in online repositories);
* Selection of an appropriate generic learning design;
* Refinement/adaptation of the generic learning design for the educational context/setting;
* Access to existing learning object repositories to search and retrieve suitable learning objects that can be used within the adapted learning design;
* Inclusion of meaningful metadata (description) at both the learning object and unit of study levels. This metadata should be suitable to support reuse by other designers (authors) and provide objective targets for adaptation and customized delivery;
* Delivery of the customized learning design with associated learning objects (i.e., the unit of study) via the appropriate hardware device and/or network.
The implementation of digital learning objects of different file formats or the combining of a number of file formats requires a delivery mechanism that considers the needs of different users. For example, a unit of study that incorporates learning objects consisting of images, audio files, text, and multimedia applications may need to be delivered in different versions according to the platform used by the learner--whether it is a desktop computer, hand-held device, or other system. (It is envisaged that the use of peripheral devices such as printers would form only secondary targets after the content has been initially delivered to a more interactive platform.)
An effective implementation of a unit of study incorporating learning objects will need to address issues of authoring--both new content at the learning object level and new context and adaptation appropriate for the learner.
To achieve these objectives, the SLDF will be implemented within the broader based MPEG-21 multimedia framework. This involves using the unit of transaction in MPEG-21, the digital item, as the mechanism for structuring and transporting all objects in the unit of study structure; This concept is further expanded below in Section 4, The Smart Learning Design Framework. Designing this system to be compliant with the MPEG-21 standard is appropriate since MPEG-21's vision is "to define a multimedia framework that will enable transparent and augmented use of multimedia resources across a wide range of networks and devices used by different communities" (Rump, 2002, p. 3).
Exploiting MPEG-21 brings several advantages to the learning object arena. These advantages can be summarized as follows.
* MPEG-21 is an international standard, which will be used across a wide range of industries. This ensures that objects produced from the SLDF can be made interoperable with the broad range of infrastructure being developed for industries such as Music and Broadcasting.
* Digital items can be adapted (configured) to the usage environment, which can include such things as user capabilities and preferences (Vetro, Perkis, & Devillers, 2002) and different terminal and network requirements.
* Digital items are capable of being accessed over a network (e.g., over the Internet), on removable media (e.g., CD-ROM), from broadcast content, and on local storage (e.g., internal hard disk).
* Digital items can contain resources of any type (from digital MP3 and JPEG to physical exhibits in museums) (Iverson, 2002a), including those specified by the content types commonly used in learning objects.
* Resources included in a digital item can have their intellectual property rights protected (Bormans & Hill, 2002).
* Using Digital Items to deliver learning objects allows sequencing and decision making to be made during multimedia content delivery (Bormans & Hill, 2002). This allows the tailoring of learning objects to users' requirements, thus ensuring an appropriate and contextualized educational experience.
* Access and usage is easily monitored and recorded in a digital item and event reporting is a part of the MPEG-21 framework (Bormans & Hill, 2002).
OVERVIEW OF MPEG-21
Many standards already exist for the delivery and consumption of multimedia content. However, what is lacking is a big picture to describe how these standards (either existing or under development) relate to each other (Koenen, 2001). MPEG-21's goal is to fill this gap and allow components (both existing and those under development) to be used together, thus increasing interoperability. Ensuring that learning objects can be delivered to all devices that adopt the broader MPEG-21 standard is one application of MPEG-21 in the education sector. This characteristic will ensure that learning objects are compatible with other forms of multimedia data.
The unit of transaction in MPEG-21, the digital item, is a "structured digital object, including a standard representation and identification, and meta-data" (Iverson, 2002a). A digital item is described and declared by the Digital Item Declaration. The Digital Item Declaration contains three major components (Iverson, 2002a):
* Model: The Digital Item Declaration Model defines a set of terms and concepts suitable for defining a digital item. The model allows the structure of a digital item to be visualized. The relationships between the major elements of the digital item declaration model are shown in Figure 1.
* Representation: This section defines syntax and semantics of the digital item declaration. This basically entails defining the Digital Item Declaration Language, which is based on XML.
* Schema: As the name implies, this section defines the complete grammar required to define the digital item declaration in XML. In essence, a digital item comprises three elements (Rump, 2002):
[FIGURE 1 OMITTED]
* Structure (description of the relationship between resources). An example of this structure is illustrated in Figure 1. A container allows items or other containers to be grouped into logical groupings, with descriptors that label the container also attached. Items allow components or other items to be compiled and bound with relevant descriptors. Items may also be adapted and configured according to choices that are contained within the item. Components bind a resource to all of its descriptors (Bormans & Hill, 2002).
* Resources (such as images, audio tracks, text, etc). The resources may be either internal (contained within the digital Item) or, most frequently, external to the digital item (they are defined by a reference). This reference is an unambiguous address in the form of a Uniform Resource Identifier (URI) or a Uniform Resource Name (URN) (Iverson, 2002a). Figure 1 indicates how resources are contained in a digital item and clearly demonstrates that a single digital item may contain multiple resources.
* Metadata (data about the resource reference). A resource can have an infinite amount of associated metadata (limited only by practical limits of the XML documents and files) expressed in any format (i.e., plain text descriptors, MPEG-7, XML schemas, learning object metadata, etc.). Metadata can also be associated with groupings of resources. The inclusion of metadata within a Digital Item is represented by the Descriptor field in Figure 1. Figure 1 demonstrates that a resource may have a hierarchical association with the metadata; metadata that specifically describes the resource is bound to the resource within a component, while the same resource may also have associated metadata at the item and component level.
Currently, the MPEG-21 standard consists of nine parts. Of these, parts 3, 4, 5, 6, and 7 are those most pertinent to the structure of the SLDF. Part 7 of the MPEG-21 standard is Digital Item Adaptation (DIA). This part defines a wide-ranging set of metadata that can be used to describe user environments, preferences, and terminal capabilities. Beyond the descriptors, it provides a useful set of tools that allow bit streams to be adapted and user sessions to be transferred between devices. While the technical details of this part are beyond the scope of this paper, the consequences for unit of study and learning Object delivery (which are delivered as digital items in the SLDF) are significant. DIA allows a digital item to be adapted in a network such that it can be viewed effectively on different devices and tailored to different users.
Parts 5 and 6 of the standard provide a Rights Expression Language and Rights Data Dictionary (RDD). The latter guarantees that all users can talk about the legal terms in an interoperable manner. For example, what is meant by play in one country or by one user needs to be identical to the term as used by another user in an entirely different culture. However, the average user is unlikely to be concerned with the details of the RDD. Rather, the licenses are formulated in the Rights Expression Language that will become a part of everyday usage. These licenses are granted to a user according to a set of conditions, and allow the specification of exactly what a user can do with, in our case, a learning object. The expression of the ability for a student to use a picture in a school project but not to distribute it to his/her friends, or to explore and utilize an item for a defined period of time are useful concepts in the educational arena. MPEG-21 thus provides a rich mechanism for the usage of content while retaining and clearly stating the rights of the creator.
Part 4 is named Intellectual Property Management and Protection (IPMP). Succinctly, this is MPEG terminology for security and defines ways of using security (encryption, authentication, etc.) mechanisms to enforce the rights and licenses that are expressed by the Rights Expression Language. Apart from obvious concepts such as securing exams, ensuring mark integrity, etc., the IPMP framework under development in MPEG-21 will guarantee the ability to create a trusted learning environment in which users (creators, educators, and students alike) can share and use content effectively. The final part of the standard, which is of relevance to this paper, is Part 3, the Digital Item Identification, which allows elements within a digital item, or a digital item itself, to be uniquely identified. This is vital for the correct enforcement of rights and security mechanisms (Iverson, 2002b).
THE SMART LEARNING DESIGN FRAMEWORK
Concept and Overview
The SLDF proposes to represent units of study using a hierarchical structure based on MPEG-21. This structure presents a seamless mechanism where various learning objects and other units of study may be grouped, while still retaining the rights, metadata, and functionality of the individual learning objects. This retention of rights, metadata, and functionality at each level of the proposed SLDF creates a clear hierarchical structure where the complexity of the objects/units of study increases as the level of the hierarchy increases. In addition, the metadata becomes less objective (data-based) and more subjective (context-based) as progression is made up the hierarchy. The unit of study metadata describes the pedagogical approach and sequence in which the embedded content is to be consumed while learning object metadata describes the specific resources. An overview of the SLDF hierarchical structure is provided in Figure 2.
[FIGURE 2 OMITTED]
As introduced in Section 2 (Background) above, the lowest level of the proposed SLDF structure is the learning object. A learning object is defined as a pedagogical unit that cannot be broken into smaller sub units; it represents the smallest autonomous unit in the SLDF. Each learning object is represented as an individual MPEG-21 digital item. This structure allows the learning objects to have individual metadata and rights protection and facilitates the sharing and storage of the learning objects in large educational repositories that support the broader MPEG-21 format.
At the higher levels illustrated Figure 2, multiple learning objects or units of study may be aggregated to form a new unit of study. Each unit of study may take a variety of forms, such as a single task, a series of activities, or an entire subject or course. A unit of study is also represented as a MPEG-21 digital item and exploits the hierarchical structure of digital items to include the learning objects (themselves individual digital items) as resources. This format permits each unit of study to have unique metadata and rights embedded, while retaining the rights and metadata of the included learning objects and units of study. In addition, the use of the MPEG-21 digital item construct at each level of the hierarchy ensures that all of the components conform to the broader international standard and thus presents distinct advantages for sharing, reusability, and adaptation.
The three-level structure illustrated in Figure 2 is only one example of how the SLDF could be implemented. The SLDF has the flexibility for the designer to add or remove levels of the hierarchy as required.
Another important advantage of the SLDF is that due to implicit retention of metadata at each level, the entire structure may be adapted and delivered to meet educational context and user requirements. An example of this process is a unit of study, where individual learning objects that contain images could be physically transcoded (rate adapted) to suit delivery on a hand-held device while choices in the unit of study sequence could simultaneously be restricted to meet the learners' pedagogical context (i.e., educational background or prior performance in the course, which would be represented via user descriptors).
As described in Section 4 (The Smart Learning Design Framework--Concept and Overview) the smallest autonomous unit in the SDLF is the learning object. This unit has its own unique metadata and is suitable for storage and sharing via large learning object repositories. To provide a pedagogical description for the learning objects, the IEEE Learning Object Metadata (LOM) standard (IEEE, 2002) is proposed.
The IEEE LOM standard refers to a learning object as "any entity, digital or non-digital, that may be used for learning, education or training" (IEEE, 2002, p. 6). Learning Object Metadata (LOM), using the LOM v1.0 schema base, provides a complex description of a learning resource. Using XML, the LOMv1.0 schema base is hierarchical, a format that is compatible with MPEG-21 metadata requirements. However, recent research has identified limitations with LOM for providing meaningful pedagogical description (Suthers, 2001; Friesen, Roberts, & Fisher, 2002). Provision is made within the LOM standard for extension and additions and the current research focus for this project is investigating suitable extensions to the pedagogical LOM descriptors, which will lead to the development of a metadata application profile.
IMPLEMENTATION OF THE PROPOSED SLDF
To allow seamless creation of MPEG-21 digital items based on the proposed SLDF structure, a set of prototype software tools have been developed. These tools remove the complexity of conformance from the view of the author (i.e., teacher or instructional designer) and provide a simple interface for digital item authoring and metadata editing. This concept makes all the technical complexity associated with structuring the data transparent to the author and enables the author to concentrate on the pedagogical structure and relevance of the current design.
Learning Object Editor
The primary software prototype developed thus far is the Learning Object Editor (LOE). The LOE presents a user-friendly graphical interface that allows resources and metadata to be seamlessly grouped together into a conforming MPEG-21 digital item. The concept is visualized in Figure 3.
[FIGURE 3 OMITTED]
The most relevant component of the LOE for this forum is the Pedagogy tab. By clicking on the Pedagogy tab the author can select the relevant technical and pedagogical descriptors for the selected resource from a pull-down menu. The menu lists all of available descriptors and when selected, the corresponding descriptor is written in conforming XML format to the digital item. This process is displayed in Figure 4.
[FIGURE 4 OMITTED]
For maximum flexibility during the formative stage of the tool, the full set of LOM descriptors was included. It is envisaged that in the final version of the editor, authors will be presented with a more user-friendly interface or wizard to assist them by presenting only the metadata pertinent to the application profile. Additionally, metadata that could be gained directly from the resource itself or from a user-profile would replace time-consuming addition of information for each term.
Unit of Study Prototype
In addition to the LOE, an initial Unit of Study (UOS) prototype has been developed. The prototype provides a graphical interface that permits the user to generate a UOS template. The template produced comprises an MPEG-21 digital item structured according to the learning design employed. Once generated, it is envisaged that the template will be augmented by including the appropriate learning objects (digital items) as resources. The aim of the tool, at this stage, is to explore the issues of packaging the content into a MPEG-21 digital item, embedding resources, rights and metadata.
Figure 5 illustrates the initial generic templates produced for purposes of testing the prototype. Adoption of this concept allows a range of templates to be included in and added to the authoring software suitable for units of study ranging from a simple activity to a full course. Authors are guided by a wizard.
[FIGURE 5 OMITTED]
A welcome window is initially displayed in which the author may select an existing template from the available list or choose to develop a new template. If the author nominates to edit an existing template, a list of Digital Item Declaration template files from the templates folder is displayed (Figure 5). The author may choose to open any of the available templates. The author is also given the flexibility to open a template stored in an alternate location such as local or network drives.
Once chosen, the template may be opened for editing. If the cancel button is selected, the wizard will go back to the welcome window. When a chosen template is opened, the unit of study is displayed in a hierarchical form (Figure 6). Within this form are groups that represent the resources of the UOS. (Note, these resources will be later added as the proposed learning objects.) In the example shown in Figure 6, the subject is structured into groups of readings, outline, formal material, and communications. At this stage, there are four editing options available to the author: add another group, remove a selected group, rename an existing group, or clear the entire template.
[FIGURE 6 OMITTED]
The Create a New Template window functions in the same manner as the Edit an Existing Template window. The only difference is that when creating a new template the author sees only a single group, from which further groups, as appropriate to create the new template, can be added.
When the finish button is selected, the designed template is written as a new DID to an XML file. This template file can then be augmented by adding the appropriate Learning Objects (created previously in the LOE), metadata, and rights.
The project team has begun to identify the requirements of a metadata application profile based on LOM suitable for the higher education context. This will be formally documented and then applied as an option within the Learning Object Editor tool. The next phase of research is to develop specifications for the Electronic Performance Support System (Northrup, Rasmussen, & Pilcher, 2001) that will assist teachers and instructional designers to construct units of study based on generic learning designs and incorporating learning objects and metadata as appropriate. This process will be tested through the development of a unit of study based on a generic form of a case-based learning design that will be extracted from its original context (Bennett, Harper, & Hedberg, 2002) and applied to a new learning situation. Ultimately, this will be implemented with the software tools discussed in this paper to allow the construction of a unit of study and packaging within the MPEG-21 framework. In addition, investigation of an appropriate metadata schema suitable at the Unit of Study level is an imperative the research team needs to address.
A platform-independent structure for representing learning objects and incorporating them into learning designs has been presented. The proposed method is a hierarchical structure based on the MPEG-21 platform that will utilise a metadata application profile based on LOM to provide metadata description at the lowest level of the hierarchy. By employing MPEG-21, this structure ensures that all objects produced will conform to the broader international standard. It also allows unique metadata and rights protection to be embedded at each level of the hierarchy. The structure also supports adaptation of the resources to suit user and network requirements.
A set of prototype software tools that provides a graphical user interface has been developed. These tools make the technology transparent to the author and allow simply authoring of conforming items.
Further research and development is underway to investigate metadata application profiles suitable for both learning object and unit of study digital items. These profiles will provide the core for adaptation of the objects to meet the users' pedagogical context.
The work reported in this paper forms part of a major research project, A Smart Learning Design Framework (Barry Harper, Ian Burnett, Jason Lukasiak, Lori Lockyer, Sue Bennett, and Shirley Agostinho), which has been funded through the Intelligent Environment Program of the Smart Internet Technology Cooperative Research Centre: http://www.smartinternet.com.au.
(1) Reproduced from Bormans & Hill, 2002, p. 7
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JASON LUKASIAK, SHIRLEY AGOSTINHO, IAN BURNETT
GERRARD DRURY, JASON GOODES, SUE BENNETT
LORI LOCKYER, AND BARRY HARPER
University of Wollongong, Australia
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|Publication:||Journal of Educational Multimedia and Hypermedia|
|Date:||Dec 22, 2004|
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