While we are willing to accept articles on all manner of topics, we would like to encourage our authors to help Nupedia achieve breadth before depth. Therefore, we encourage that they write brief articles of one to five paragraphs, of the sort that one finds in a good one-volume desk reference on a subject area. At the beginning and end of a brief article there will be a link to a longer, more in-depth article on the same topic. Below the link to the longer article, there will be links to articles on subtopics, which go into even more depth, on selected points, than the longer article. A brief article can be simply the first few paragraphs of a longer article, as long as the paragraphs can stand alone.
In some cases, we might simply to have a brief article by itself. It is also possible that we will want an article slightly longer than five paragraphs, say 8-10 paragraphs--a "medium-length" article--that can stand on its own, without any brief introduction and without a longer article on the same topic to accompany it.
So there are three types of Nupedia articles planned: (1) a brief, one-to-five paragraph introduction to a topic, which may or may not stand alone; (2) a medium-sized article, which must stand alone; (3) a longer article, which must be accompanied by a brief introduction.
While very lengthy articles will always require a brief introduction, writers and editors might decide that a topic warrants something over five paragraphs, but nothing as long as, say, 3,000 words. In that case, they have the option of creating a "medium-length" article that will (1) appear in the place where the shorter article would normally appear and (2) not have an associated longer article. This type of article should not exceed 1,500 words.
A longer article may be of any length, but if it grows past, say, 3,000-5,000 words, then it should be truncated in some fashion, with individual parts of the article developed in more detail as subtopics; links to these subtopics should be added to the original category page below the link to the longer article. There are no limits to the degree of specialization Nupedia articles can exhibit.