Learning Objects and Ontologies

2.3.1. Learning Objects

“Learning objects have recently become a popular resource for e-learning and web-based teaching” (Wiley, 2000). Because of their emphasis on reusability, learning objects offer a

solution to the exponential increase in educational information available and the parallel decrease in investment in educational technology support (Metros & Bennett, 2004). The literature

provides different definitions for the concept of learning objects, also called information, educational, or knowledge objects, which reflect the interpretations of the various communities (computer scientists, educators, commercial publishing houses, and libraries) involved in their development. While instructional designers tend to see learning objects primarily as reusable “chunks” of digital content, computer scientists consider learning objects more as containers of content andinstructional components of learning management systems based on object-oriented programming.

The most “official” definition of what a learning object is comes from the IEEE Learning Technology Standards Committee (IEEE LTSC): "[A learning object is] any entity, digital or non-digital, which can be used, re-used or referenced during technology supported learning” (IEEE Learning Technology Standards Committee, 2002). Such an open definition implies that learning objects may come in a wide range of shapes and sizes, as well as complexity of structure and density of content. They can be in the form of pre-arranged packages of content, such as

those often found in the education publishing industry, or they can be small units aggregated dynamically as the result of RSS-driven processes as envisioned by e-learning pioneer Stephen Downes (2004). As Wiley (2003a) argues, there are two “orthogonal paths” in instructional technology related to learning objects that embrace two colliding instructional philosophies. On the one hand, there is the automated instruction approach that does not include the mediation of an instructor. On the other hand, there is the social constructivist approach that tends to include more and more humans in the instructional context through various participatory applications, including wikis and blogs.

The multiplicity of interpretations of what a learning object is implies a broad array of options for designing the objects but offers no indications of what characteristics make learning objects effective in teaching practice. This ambiguity is seen as one of the reasons why this promising educational technology has not yet met expectations in terms of impact on teaching practice and rapid adoption by educators (Metros, 2005).

To facilitate the access and use of digital primary sources for the education community, the UNC-CH University Library has decided to repurpose portions of digitized historical content from its collections in the form of learning objects. In an attempt to better meet the instructional needs of history and social studies teachers, the design of the learning objects has been guided by the findings from user tests and focus groups conducted by the Library staff with educators over the last few years (Norberg et al., 2005).

The resulting learning objects diverge from the more common notion of a learning object as conceived and applied by computer scientists and instructional technology companies that requires little if any role for the human instructor. The UNC-CH University Library learning objects are primarily intended as instructional building blocks for “mediated” or “instructor-led learning” and are intended to be purposed and repurposed by teachers for a variety of

instructional objectives. Such an approach is not only supported by the findings of the UNC-CH Library user studies, but it is also endorsed by relevant literature that emphasizes the value of social interaction as a necessary condition for effective learning. As Artacho asserts, “Learning is a process between teachers and students, and teachers tend to have their own view of learning and the way they use learning materials in class” (van Kasteren, 2003, p. 13).

Criticism is increasingly emerging about the capability of “learning objects standards and recent learning design approaches to effectively manage the requirements for active pedagogy in learning contexts” (Lytras & Naeve, 2006, p. 484). More research to deepen the understanding of “learning principles and articulated pedagogies” embraced by learning objects is needed (Metros & Bennett, 2004, p.3). Metros and Bennett further stress the importance of analyzing existing educational practices, aspects of innovation adoption, and the educational context in general for developing effective models for learning objects.

There is a growing body of research addressing the issue of contextualization or customization of learning objects for specific audiences or learning objectives (Phillips,

Hawkins, Lunsford, & Sinclair-Pearson, 2004; Razmerita, Gouardères, & Conté, 2005; Weihong Huang, Webster, Wood, & Ishaya, 2006). The trade-off between contextualization and

reusability is hotly debated within the learning object community and there is a need to find management solutions that enable both dimensions (Wiley, 2003b). Learning objects that are highly contextualized can serve specific audiences and/or learning objectives quite well, but their reuse for other audiences or other objectives may be limited. On the other hand, if a learning object is not contextualized, it may not serve educators who have limited time to provide the necessary customization.

Organizations such as the IMS Global Learning Consortium (IMS)22 and the IEEE23 have

developed learning object metadata standards to provide a context for educational resources. IMS (2001) and IEEE Learning Object Metadata (IEEE LOM)24 are major educational metadata schemas that describe resources primarily from the point of view of their role in the pedagogical context and their place in the curriculum. As Sosteric and Hesemeier (2002) point out,

educational metadata standards help to provide the infrastructure for contextualizing learning objects, a role that in the past was played directly by instructors.

By and large, much of the research conducted on the application of semantic web technologies to learning objects has focused on management issues involving reusability and contextualization. For example, ontologies have been designed to enable the aggregation and sequencing of learning object content on the basis of pedagogical objectives and learning tasks (Mohan & Brooks, 2003; Qin & Finneran, 2002; Gašević, Jovanović, & Devedžić, 2004). Another possible way to add context to learning objects without limiting their usability and re- usability is through the semantic annotation of their content. The use of semantic metadata has the potential to enable search, aggregation, and navigation functionality that better serve the information-seeking needs of the community of educators and learners.

2.3.2. The Challenges of Ontology Development for Learning Objects

As the literature shows, ontologies and ontology-driven metadata have the potential to significantly enhance information systems, including digital libraries and educational

applications such as learning objects. However, ontologies are a rather novel tool in the context of the web and digital libraries. Despite the large corpus of ongoing research on ontologies, 23 _{http://ltsc.ieee.org/.}

primarily as the key infrastructure to enable the semantic web, real-scale applications are still limited. The number of ontologies developed in a wide range of domains is rapidly increasing, but few have left the research labs (Hepp, 2007). The technical and economic challenges

associated with the development and deployment of a domain ontology are far from trivial. The cost benefits of ontology development are not yet known (Bontas & Mochol, 2006) and as Ding and Foo (2002) point out, “manually constructed ontologies are time-consuming, labor-intensive and error-prone” (p.123). Critical issues of scalability, interoperability and adaptability are also part of the ongoing debate.

There is a clear need for more evaluation studies to assess the practical effectiveness and usefulness of semantic web tools and applications, including ontologies. One of the underlying questions addressed in this study is whether or not developing and deploying a domain ontology for a collection of learning objects is, simply stated, worth it. One way to assess the usefulness of such a tool is to maximize the development process by understanding and involving the end users.