Synthetic.

One collects, reduces, consolidates, and unifies existing knowledge. This includes the writing of surveys and the development of textbooks for new areas, which are necessary for continued development. Accepted standards of quality include:

• The new presentation should improve the conceptual unity, clarity, and ease of learning of a body of knowledge. It may expose interconnections and relationships that were previously difficult to see, perhaps by abstracting away obscuring details or by introducing a new unified terminology.

• The work should be original. No one should have pulled these ideas together before or expressed them so well.