As we start wrapping up this series, we turn our attention to the final section of the manuscript, where authors strive to wrap everything together into a nice tidy package–I’m speaking of course of the Discussion (or Conclusions, or Results and Discussion, depending on the journal). Writing an interesting and informative Discussion section can be a challenge, but keeping a couple of key points in mind should make things easier.
Understand the journal you are writing for and its style.
This has been a common refrain throughout the past several columns, in part because so many authors treat journals and journal styles as interchangeable. But you can gain tremendous insight into how you should present your study for a particular journal by closely examining how its articles are structured.
At BioTechniques, we ask for a combined Results and Discussion section in our Report articles. Why? In the studies we publish, the experiments are done to support the development or refinement of the method in question. So explaining the results naturally moves into explaining their significance and value to readers who might be interested in trying the new approach in their labs. Contrast this with studies appearing in basic research journals, where multiple experiments are performed to examine a biological phenomenon. The results must be reported and interpreted based on the state of the field before a more general conclusion can be drawn.
Are these statements from the Results or Discussion section?
- “In order to show that the microsatellite regions that were sequenced were also useful for the development of polymorphic markers, we synthesized primers flanking 29 microsatellite regions in F. circinatum. Of these, 19 produced single amplicons, and their application on a set of only eight F. circinatum isolates showed that 13 primer pairs targeted polymorphic microsatellite loci (Table 2).”
- “The results of this study clearly demonstrate that sequencing essentially all enriched PCR amplification products for microsatellite regions using 454 genome sequencing technology represents a superior alternative to conventional screening of clone libraries using Sanger sequencing.”
- “At the time of this study, the cost of generating the 1692 unique sequences that were obtained for F. circinatum through pyrosequencing would have been 62% greater if Sanger sequencing was employed. When only amplifiable micro-satellites are considered, pyrosequencing resulted in a 276% cost reduction per microsatellite.”
The answer is that all three sentences appeared in the Discussion section. I hope it is clear from these examples that the difference between a statement in the Results section and one in the Discussion section can be hazy. So how can you set up separate Discussion and Results sections to present your research more effectively?
- Present the data in the Results section. Don’t put in too much analysis or interpretation here–save that for the Discussion. In this way, everything will be in the right location, and readers will not get déjà vu when reading your Discussion section. If you spend a significant amount of time explaining the rationale behind an experiment or the meaning of the data in the Results section, this could be an indication that you are blurring the lines between the Results and Discussion.
- Leave very specific data out of the Discussion section. In the quiz above, the point the authors are trying to make in sentence #1 (suggesting that many of the regions sequenced should useful for the development of polymorphic markers) is important, but the specifics on primers and amplicon numbers would be better suited to the Results section with commentary on the implications of these data saved for the Discussion section. To illustrate this concept more clearly, look at sentence #3 from the quiz. Here, the authors detail the 276% cost reduction associated with sequencing only amplifiable micro-satellites. Specifics on how this cost reduction was achieved can be found in the Results, but the significance of these data is best detailed in the Discussion.
Don’t oversell the future.
I cannot tell you how many times I have gone through the Abstract, Introduction, Materials and Methods, Results, and Discussion section of a very well-written manuscript only to come to the final paragraph and find a discussion of incredibly far-reaching future prospects or over-interpretation of the study’s implications. In the end, possibilities for the future should follow as logically from the data presented in the Results as the conclusions you make earlier in the Discussion.
In my experience, to overreach only brings down the hammer from reviewers. And for what–providing some last minute excitement more than anything else? While it might be enticing to end on a speculative note, wrapping things up more directly by tying everything back to that all important “Here we show…” statement in the Abstract is often a much better way to conclude any manuscript.
Results and Discussion sections can be scary for young writers. They provide the opportunity to truly explain and interpret your findings and how they relate to prior work. By presenting your data in a logical manner, with the results and discussion in their correct locations, and not overselling your study’s implications, you should find it easier to write a manuscript that will sail through the choppy waters of the peer-review process.
In our final column in this special series, we will turn our attention to communicating the data more effectively using well-constructed Figures.
BioTechniques Special Series: Manuscript Tips