The purpose of the introduction is to motivate the work, describe why solving a particular problem is important in the larger context, describe difficulties in solving this problem, and describe approaches that have come before this work. Introductions often include (essential for conference papers) a concise paragraph on the contributions of this work to the field. The introduction section generally concludes with a paragraph giving a rough outline of the paper (this is almost mandatory in some types of journals, e.g., JMLR, JASA, AOAS).
One common mistake with Introductions sections: No results or conclusions should be included. We are setting the stage, making the relevance of the results clear in the larger context and scoping their impact, but not giving away the punchline. The reader gets to make up their mind given the methods and results.
Tips for writing the introduction
Before writing the introduction, think hard about the general ideas that are necessary for the reader to know for this paper to be relevant. Each paragraph should cover one of those ideas. E.g.,
- What is a BLURG? Why is a BLURG important <in this field>? What is the impact of studying BLURGS?
- How do we experimentally assay BLURGs? What are the limitations of these assays? OR
- What types of methods exist to statistically study BLURGs? What are their limitations?
- Why is our approach different than previous work? How does it address gaps in our current methodology?
- What are the three main contributions of this work?
- What is the basic experimental design of this paper? How is this paper laid out?
The introduction is also the place to define all of the concepts used in the paper. All acronyms to domain-specific ideas should be defined here (e.g., SNPs, TFBSs, DHSs).
The introduction should contain short, easy to read sentences. (Nearly) everything that is mentioned about definition, context, and existing approaches should be supported by citations.
The paragraph on contributions should be very specific. If it sounds too narrow, you are probably doing it right. Write this paragraph last, after you are sure exactly what the contributions of the paper are, and use pieces of this paragraph in the cover letter. Most papers make small (but important) contributions:
The contributions of this work to this research area are threefold. First, we reformulate the model to create identifiability in the parameter space. Second, our collapsed sampler mixes well and is robust to different priors with respect to mixing rate. Third, we show that our method can be used to solve an important problem and includes well-calibrated uncertainty estimates.
- CiteULike: Organize and gather bibliographies. Export collection of papers to .bib file. Free and on the web.
- Mendeley: Fancier way to organize and gather bibliographies. Drop PDFs into the interface and it pulls the reference. Export collection of papers to .bib file. Free (up to a point!) and on the web.
- Google Scholar: surprisingly easy to pull BibTex reference to all papers and books (find paper, hit ‘cite’, hit ‘Export to BibTex’)