Design and Reusability of Learning Objects in an Academic Context: a new Economy of Education?
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Learning Object RepositoriesLearning objects are stored in databases called learning object repositories. There are two major types of repositories: those containing both the learning objects and learning object metadata, and those containing metadata only. In the latter case, the learning objects themselves are located at a remote location and the repository is used as a tool to locate learning objects. In the former, the repository may be used to both locate and deliver the learning object. Most learning object repositories are stand-alone. That is, these repositories function a lot like portals in that they contain a web-based user interface, a search mechanism, and a category listing. Another major class of learning object repositories functions more like a database attached to another product. An LCMS, for example, may contain a learning object repository intended for its exclusive use. Two major models for learning object repositories exist. The most common form is a centralized form in which the learning object metadata is located on a single server or website (the learning objects themselves may be located somewhere else). An alternative model is the distributed learning object, in which the learning object metadata is contained in a number of connected servers or websites. Distributed learning object repositories typically employ a peer-to-peer architecture to allow any number of servers or websites to communicate with each other. The following are examples of some learning object repositories:
Learning Content Management SystemsLearning objects are typically small, consisting of no more than the equivalent of an hour or two of instructional time (there is some debate as to how small a learning object may be and whether educational content must contain pedagogical features, such as a statement of learning objectives, in order to qualify as a learning object). Most educational institutions deliver larger chunks of instruction, called courses. To create a course, therefore, a set of learning objects must be assembled into a package. Packages organize learning objects sequentially. In order to create a course out of, say, a dozen lessons, where each lesson is a separate learning object, a course author arranges these lessons into a sequence. In some cases, where the learning objects are smaller units, course designers may need to create lessons composed of a sequence of individual modules, then the course as a whole out of the sequence of lessons. However created, the sequence of objects is used to define course-specific entities as the course outline or table of contents. Packages are created using a Learning Content Management System. While a course author could locate and assemble learning objects by hand, it would be tedious and unproductive to do so. Courses created using learning objects are typically created using a development environment called a Learning Content Management System (LCMS). The LCMS performs two major functions: it provides authors with a means of locating learning objects, and it assembles them into standards compliant learning packages (or courses). (Ellis, 2001) Though many types of LCMS are available, the typical LCMS will contain four essential features: an authoring application similar to the computer assisted software environment (CASE) described above, a collection of learning objects (called a repository), a means of sending the completed course to a delivery system (called a delivery interface), and administration tools. http://www.internettime.com/itimegroup/lcms/IDCLCMSWhitePaper.pdf http://www.internettime.com/itimegroup/lcms/ Using an LCMS, a course author defines major features of the course: its topic area, say, or its grade level. The author then instructs the LCMS to search through the learning object repository for relevant resources (because the data is in XML, the search can be very precise). From the search results, the author may review a learning object or select it for inclusion in the course. The LCMS retrieves the object metadata from the repository and inserts it into the course package. The LCMS automatically adds institution-specific formatting and prepares the package for delivery.
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