The Graduate Office has this to say about dividing chapters into sections:
Each subdivision of the thesis bears a title that is prepared in a style unique to that subdivision level; i.e., each level has a format that is used only for that level of subdivision title throughout the thesis. The subheading scheme must take into account the chapter with the maximum number of subdivision levels, and the hierarchy once chosen must be adhered to throughout all major divisions of the thesis.
So we must come up with a unique format for each level of sectioning command. The 2000-era stylesheet use boldfaced, normal-sized type for each command, and distinguished them by their spacing:
Section titles were numbered and flush left. Continuation lines were indented to align with the text just after the section number.
Subsection titles were numbered, and indented the same amount as the normal paragraph indent. Continuation lines were actually unindented about 8 points relative to the beginning of the section number; surely this is an error—it looks terrible.
Subsubsection titles were unnumbered and set flush left.
In the author's opinion, the indented subsection titles look
rather odd. In theory, the requirement that different levels
of sectioning have different appearance is satisfied perfectly
well by having different section numbers: one for
\section, two for
However, in order to make the different levels more visually
distinct, and because the Goudy dissertation formatted with
the old stylesheet passed inspection, we will implement
these same rules (without the aforementioned problem with
continuation lines in subsection titles), with one exception:
The title of a
\subsubsection command will be
unnumbered and boldfaced, but run-in to the following