What I’ve been saying about the breaks between chapters also applies to the breaks between sections inside a chapter—except that it would be more unusual to have a cliffhanger between sections.
I’m fond of very short chapters without sections. Often chapters of only 3 to 6 pages, the length of other people’s sections. I’m writing what I enjoy reading—always a good principle!—and I know very short chapters suck me in.
I suppose the idea of, say, a twenty pages chapter divided into half a dozen sections is that the reader doesn’t stop at the end of a section but keeps going through to the end of the chapter. True enough, it works that way for me. But, when I do reach the end of a twenty-page chapter, it’s like a finishing post, goal achieved—and I stop dead.
What sucks me in with very short chapters is the temptation to read just one more. Only a few pages … so I read it, and then there’s the next chapter holding out the same temptation. It can suck me in over and over again, until I lose all track of time.
That’s me as a reader. As a writer, I like the way very short chapters tend to set up a rhythm. Writing becomes very easy for me when I find that rhythm.
The advantage of sections is that they’re far more flexible. You can have one section over twenty pages long followed by another section under twenty lines long. Not conducive to a rhythm, but there are times when these lengths come in very handy. It would look odd to have chapters varying so much in length.