This post continues the paper-writing self-help series for PhD students directly from where the previous post ended.
Once you have decided the key point of your paper and have settled on its main conclusion, the next step is to choose what results go in. This choice should be made with care: now that you have a point to make, plan your paper so that everything else supports this point. The rest should go! The best papers are often quite minimalistic: they drive their point home with essential ingredients only. Papers that contain tons of unrelated results are difficult to comprehend, because the reader is left wondering where to focus her attention. Clutter reduces clarity. Always konmari your paper! Keep what makes it happy and discard everything else.
Continuing with the film industry analogy, the process of going through your results and deciding what to keep resembles the process of editing of a Hollywood movie. After the movie has been shot, the director and the editor start working with an abundance of raw materials that are to be sculpted into the final product, the theatrical cut. The goal is to assemble the film from the shots and scenes that best support the storyline, cutting out footage that is not essential and that doesn’t have the emotional impact that the director desires.
Your paper is your theatrical cut. Use only the elements it needs, and leave out the rest.
Cutting out material and deciding not to use some of your results may feel difficult and painful – you spent a WEEK on that plot! But, believe me, it is for the best. If you want your work to have impact, it has to be read and understood, which is greatly hindered if there is too much unimportant or unrelated information to absorb. Clutter draws attention away from the point that you want to make, and leaves the reader exhausted.
Perhaps it is because of the pain caused by discarding perfectly-good-yet-unimportant results that most journals nowadays allow for a extended special five-hour-long director’s cut in the shape of a Supplementary Information document with an unrestricted page count. You can dump all those raw materials that didn’t make it to the theatrical release to the SI, so that they can safely be forgotten and ignored by the rest of the world. But now your week spent making that plot means at least something.
But back to your cut – how to choose the results that are to be included and that support the key result?
Let us see how far we can push the film script analogy discussed earlier. A typical film script begins with the Setup phase where the characters and the setting are introduced, then moves on into the Confrontation phase where the characters are put in interesting trouble, and finally there is Resolution (epic fight in space followed by an exploding Death Star or similar). This may be followed by a brief Epilogue (with or without frolicking ewoks). If we divide our results into these four categories, Setup and Confrontation contain results that are needed for getting to the main result, for building up excitement and for leading the storyline to its climax. Resolution is the main conclusion that we discussed in the previous chapter. Epilogue shows what follows from the Resolution.
The Setup category contains plots and results that are required for the reader to make sense of the context, setting, your experiment, and/or your data (like, basic statistics, and so on). Schematic diagrams that visually explain the concepts that your paper works with also fall into this category; always include a schematic diagram or two!
The Confrontation phase brings the story closer to the final revelation that you aim to make; it highlights the open important question that you address. You can do this, for example, by showing empirical results that are surprising and cannot be explained by existing theories, and then providing an explanation as the Resolution of your storyline. You can also build up excitement by presenting a number of competing hypotheses or models, to be then shot down by your results (except for the one model that matches with your data and provides your Resolution). Or, you can begin by displaying some surprising system-level results or statistical observations and then home in on their detailed explanation in the Resolution phase.
The Resolution category should only contain your main result and key point; one to two figures.
The last category of results, the Epilogue, is more important than the last couple of minutes of a blockbuster film. These results are presented after the main result, and serve the purpose of highlighting its significance. One key technique is to think of some application or consequence of the main result, and to illustrate this with, say, a figure that plays the role of an example rather than that of an important stand-alone result.
If you look at some research papers published in the glossy magazines (Nature, Science, and so forth), you’ll see that great many authors apply this technique: out of the four or so plots in those letter-format papers, the first is about Setup/Confrontation, the second is the key result (Resolution), and the rest are there for showing why the key result matters, or what it means (Epilogue). For the kinds of journals that us mere mortals publish in, these figure counts may be larger–the important thing is to decide on clear roles for your results and figures and use them accordingly when telling your story.