How Resources are Organized in this Subject Guide
 
1.  Summarizing Knowledge
This first cell of the five-cell model lays out those sources of disciplinary literature that give a short overview of "what is know" at the current moment.    Categories of resources included here are such things as scholarly encyclopedia articles, textbooks, histories, handbooks.		 2.  Selective Bibliography
Analogous to Cell 1, this cell indicates those bibliographic resources that attempt to point out just the very, very best sources of literature, both the best of Cell 1 and Cell 3.  Cell 2 includes items we call "guides to the literature," didactic bibliographies, and so forth.
They are an excellent place to start one's research into a concept or topical area.

3.  Research - Information
Cell 3 is what we usually think of when we think about a discipline's literature: journal articles, books, etc.  This is the initial publication of new research findings.

4.  Comprehensive Bibliography
This is the category of bibliography that includes "everything" as opposed to Cell2, which included only that which some scholar thought was the best.  This category includes the kinds of indexing services and library catalogs we usually think of.
5. Reference, Facts, Data
While the top layer (Cell 1 and Cell 2) have to do with cumulated, synthesized, summarized communications (literature and bibliography), and the second layer (Cell 3 and Cell 4) have to do with entry information that is coming into a discipline's literature, Cell 5 has do do with the supporting reference and factual resources: directories, biographical sources, statistical data, etc.

For further explanation of how this model works, and its rationale, see this document.