Definitions for "Purposes"
The dimension of understanding that considers the awareness of the reasons that various concepts of disciplinary knowledge exist, how that knowledge is used by members of a field, and the degree of ownership and autonomy students demonstrate in relation to disciplinary knowledge. (see also "Dimensions of Understanding in this Glossary")
The objectives of an evaluation (e.g., to judge the relative merits of competing textbooks, or to monitor and report on how well a project plan is implemented) and the intended use of its reports (e.g., to help teachers choose a textbook or to help a school district carry out a special project).
A “variety of purposes” in this context would include, but not be limited to, casual conversation, formal presentations, academic discussions, and various social situations.