The L&T specialization allows training content to be used in multiple ways. For example, a learning assessment topic could be used to generate a test for students, but it can also contain information to generate answer keys for instructors. By applying different transformation scenarios to one set of topics, you can use them for multiple purposes.
The L&T specialization, like the rest of DITA, uses semantic elements, meaning that the names of the elements give insight to how they are used. For example, the <table> element indicates that the elements contain the contents of a table. In the L&T specialization, the semantic elements are specific to the specialization: the <learningOverviewbody> element contains the body of a <learningOverview> topic.
The <learningObject> element can be used within the L&T specialization to group learning topics together into one learning object. Learning plans, overviews, contents, assessments, and summaries for one lesson can be grouped together into one learning object.
The <learningObject> element also allows you to add any DITA content, even if it was not created using L&T topics.