I was recently pointed to a post The 5 pivotal paragraphs in a paper | Dynamic Ecology, that gives advice about how to structure a scientific paper. Most of the advice is good, but I disagree with one statement:
First paragraph of the introduction—you should use this paragraph to embed and contextualize your work in the context of a large classic, timeless, eternal question. What drives species richness. Or controls abundance or distribution. Or gives the best management outcome. Or explains why species are invasive. Or controls carbon flux. You of course are not going to fully answer this question. Indeed no one person, and probably even no generation of scientists will fully answer this question, but ask a really big question. You can then use this big question setup to spend the rest of the introduction summarizing past attempts to answer this question, and show how they have all failed to address the key issue you are about to address.
The first paragraph of the introduction should be the specific point of the paper, not general BS. I read far too many papers (particularly student papers) where there is a huge wad of background dumped before the author gets around to telling me what they are writing about. It irritates me—especially when I already know most of the background.
Don’t bury the specific goal of the paper at the end of the introduction—your readers may never get that far if you start out with general BS. Start with the specific goal of this paper—not the overall goal of a long-term research project or (even worse) the fundamental dogma of biology.
There is a term for this in journalism—it is known as “burying the lede”, which is considered a major flaw in news reporting. It is a similarly large flaw in scientific writing.
I recommend that the first paragraph of a scientific article give the specific research question being answered in the article, and that the rest of the introduction then be used for the contextualizing that question—why is it important? how does this study answer it? For engineering reports, the first paragraph should give the main engineering design goal and constraints, again using the rest of the introduction to say why that was important.
If the conclusions of the paper do not answer the question raised in the first paragraph of the introduction, then the question is not specific enough.