Before launching into a discussion of XML[3], it is important to understand some of the terminology that will be used throughout this paper.
.6in .5in Attribute - The characteristic of an XML element which defines the content. Example: if the elements are: class, type and color; corresponding attributes might be: toy, rubber ball and red.
.6in .5in Chunking - The process by which legacy content is coded for inclusion into the content database.
.6in .5in Content - Content is information. It may take the form of text, graphics, audio or video.
.6in .5in Database - A hierarchical distribution of data arranged in relationships, which provides quick access to information of interest.
.6in .5in Document - Strictly speaking, when working in XML there is only one super document, which contains all the content. This content fits into a common structure. We extract pieces of this super document and publish it as document instances, which may either be static or dynamic.
.6in .5in Dynamic Instance - When publishing a document instance, it may contain information that changes continuously. In defining the document publication instance, it may be desirable that every time a user opens the instance they see the most recently updated information.
.6in .5in Element - An XML element is a definition for content. Any piece of content may be defined by one or several elements. Example: class, type, and color.
.6in .5in Learning Object - the base component of training curriculum. Each learning object addresses a specific learning goal. Just how specific a goal is defined varies from system to system.
.6in .5in Metalanguage - the language that is used to talk about (expressions of) another language, the object language. XML contains and identifies content, but the XML is not the content.
.6in .5in SCORM - Sharable Courseware Object Reference Model - a set of specifications for developing, packaging and delivering high-quality education and training materials whenever and wherever they are needed.
.6in .5in Static Instance - When publishing a document instance, it may serve as a standard or reference. In defining the document publication instance, it may be desirable that users see a single, unchanging document, until any changes have been blessed by an approving body.
The next section introduces XML and discusses some of the features of XML that make it particularly appropriate for learning object development and learning content reuse.