Sidebars: Inside Out One of the reasons that learning objects are so difficult to define is that they can be virtually anything. Any stand-alone chunk of information capable of teaching something can be a learning object. Examples include a chapter in a book, a map, a graphic, an interactive application, a video, a wiring diagram, a simulation, and so on. As well as being any thing, a learning object can be any size. While some organizations, such as CISCO Systems Inc., have precise rules for what constitutes a learning object or an information object, definitions across the field of education as a whole remain quite loose. What might be considered a complete learning object by one educator, might just be a component of a learning object to another. In current practice, a learning object might teach a single idea or it might cluster several concepts to deliver a more substantial chunk of learning. While there many interpretations, most educators would agree that learning objects have the following characteristics

* Smaller units of learning: Learning objects usually comprise a smaller unit of learning than a course, typically ranging from two to 15 minutes.
* Self contained: Each learning object is self-contained and can be used independently of other learning objects.
* Reusable: Learning objects are reusable. The same learning object can be used in multiple contexts for multiple purposes.
* Can be aggregated: Learning objects can be grouped into larger collections of content to create more substantial units of learning.
* Tagged with metadata: All learning objects are tagged with metadata that describes the lear