Should each chapter in an extensive paper start with an overview of the chapter's contents?

Question

I'm working on a extensive paper for my study. It's about some computational stuff, has 5 chapters and will be - all in all - roughly 60 pages long. Reading some papers and theses I noticed, that often people start each chapter with some kind of an overview, describing what's going to happen next. Though on the one hand, I find this helpful sometimes, on the other hand it pulls me out off the flow of the actual work. In some papers, it seems even that certain things, which are going to come up are announced repeatedly and I feel a bit over-informed of the papers structure.

Therefore I'd like to know:
Should each chapter start with such an overview and - if yes -, when and to what extent?

Answer 1

The last time I wrote a long paper with a multistep argument, I endowed each section (there were 15 or 16 of those and the total article length was 87 pages in the 12pt font) with the "objective statement" (In this section we show that there exists a partition of the set $E$ into "cells" with the following properties ..., etc.). Moreover, I italicized these objectives. The reasons I did it were

a) some of the sections were devoted to things that are known to experts but hardly to the "general audience", so which sections to read and which to skip would heavily depend on the reader's general background

b) If you read the italic font alone, you can see the general flow of the proof without computations or technical details. You may then concentrate on "most suspicious" or "least known" places first.

I had mixed feelings about doing so too, but it looks like the readers have liked it so far. In general, the main question you should ask yourself is whether what you do will facilitate the reading. Everything else (paper economy, stylistic beauty, etc.) is secondary. If you expect 20-50 people to read what you wrote and if you can spare each of them mere 20 minutes (the minimal time needed to verify the ubiquitous phrase "direct computations yield"), you advance the general human progress by 7-14 hours already.

Note that what I did was different from the "Chapter" approach because I put only one complete logical step into each section. Also it was not about the Lemma/Sublemma/... division, which more often than not reflects the technical convenience rather than the logical structure. Some sections contained several lemmata needed to carry out the corresponding logical step and some lemmas were done in two steps.

The last thing I want to say is that, when reading, most people, including myself, prefer a repetition to an omission, and being over-informed to being under-informed, so few people, if any, will criticize you for being too clear or too slow.

Answer 2

There is no single right answer for this. A short chapter may not need a paragraph outlining the structure and content, while some chapters may have a quite complicated structure. Use the structure of the chapter to help you decide. The more sections and subsections, and the more you try to do in a chapter, the more useful an introduction should be.

If you include such a description, it should provide the user with the key information they should be looking for as they read. What level of description that should be is up to you to decide; there is no universal standard.

Answer 3

My approach is that it is almost always useful to have some form of overview, even for extremely short papers. However, this overview can range from one or more paragraphs to a single sentence.

For example, in a short paper each paragraph usually presents one or more results. I would try then to start each paragraph with a short overview sentence regarding what the sub-question is, then present the results, and sometimes conclude with a summary sentence.

Also, note that an overview does not necessarily have to interrupt the flow of a paper. In many cases, if the paper is constructed such that it follows a single narrative, it is possible for the overview to establish a conceptual connection between sections. In its simplest form this would be "Given that we found X and Y, we now asked whether Z".