Archive for November, 2009

Writing the results section

The purpose of the results section is to describe your findings as concisely and clearly as possible. In other words, be careful not to rehash your methods or discuss the meaning of your data in this section.

Organizing the results section

It often makes sense to lead with the findings that most directly address the question or problem you presented in the introduction, followed by results that are still relevant to your overall story, but secondary. One way to envision this type of organization is as an inverted pyramid (pdf), in which you start broadly with your most important findings (e.g., your model’s predictions) and then taper toward less significant results (e.g., validation data).

On the other hand, you might decide that readers need to know how your model works before they can grasp the predictions. In this case, you flip the pyramid right-side up again, i.e., start narrow with the model’s specifics and finish broadly with your major findings.

Whatever structure you choose, make sure each section and paragraph flows logically from one to the next. So, for example, although you may have completed your experiments in a certain chronological order, ask yourself if this is the best order for supporting the main message of your paper and getting readers to follow the story.

Common pitfalls to avoid

Including anything but your findings. To quote the catchphrase of the 1950s TV crime drama, Dragnet: “Just the facts, Ma’am.”

Including too many findings. Remember that the most effective scientific papers usually focus on a single story, message or bottom line. Thus, try to limit your results section as much as possible to those data that directly support the main point of your paper. If you find yourself trying to squeeze in many more, you might consider whether these additional findings should go into another paper.

  • Repeating what is shown in the figures and tables. Your text should summarize what the figures and tables show, not go through them data point by data point.
  • Losing the connection between the question/problem you posed in your introduction and the answer/solution: your results. In the best-written papers, this link is crystal clear.
  • Failing to guide the reader. See the discussion below.

Guiding the reader

With the exception, perhaps, of Materials and Methods, the results section is the most detailed one in the scientific paper. So, while it’s true that this section should primarily present your findings, it’s also true that readers need transitions, summaries and other guideposts to make their way successfully through all your data. Below are three strategies for keeping the reader oriented.

  • While you should avoid rehashing your methods in detail, do describe your overall approach briefly at the start of the results section, and at the beginning of each subsection, if needed.
  • Offer readers a one-to-two sentence summary of your overall findings for each set of experiments or analyses, before launching into all the specifics.
  • Describe briefly the logic behind performing experiments or analyses. For example: “Because A resulted in B, which is in the cascade of C (citation), we decided to see whether A was connected to C; therefore we subjected D to E.”*

Statements like these are not fluff; to fully understand your study, readers need a periodic reminder of where they are in the forest as they move through the trees. Otherwise, they can become hopelessly lost in all the details.

References

November 16, 2009 at 2:06 pm Leave a comment

Tips for writing the introduction

Here are a few things to keep in mind when writing the introduction to a scientific paper. I developed this material for a writing workshop I recently held with my students.

Main purpose of the introduction
To present the problem (an “intricate unsettled question,” a “source of perplexity”) you’ve addressed and why it’s important. If readers don’t grasp the problem, they aren’t going to care about the solution, i.e., your research.

Components of the introduction

  • Background that places your research in a broader context and tells why it’s significant (what is known)
  • Description of the knowledge gap your study fills (what is not known)
  • Statement of your problem/question/hypothesis
  • Description of your approach and why you chose it
  • Brief summary of your major findings
  • Statement of the major implication of your work, i.e., the take-home message

A simpler approach to the introduction – as an answer to three questions (Cetin and Hackam, 2005)

  • What do we know about this topic?
  • What don’t we know?
  • What are we now showing?

Structuring the introduction

One way to visualize the structure of the introduction is as two funnels connected by their narrow tips.

Common pitfalls

  • Failing to state clearly the problem and its significance. In a study by Bordage (2001), “insufficient problem statement” was one of the top reasons reviewers gave for rejecting manuscripts.
  • Treating your introduction like a literature review. The background you include should be just enough for readers to understand what your research problem is and why you chose it. Anything more could cause readers to lose interest.
  • Not reviewing the literature carefully enough. Omitting a key paper could lead to embarrassment – and negative reviews.
  • Underestimating the importance of the introduction. Although your findings and conclusions are the meat of your paper, the introduction is where you set the stage for them. Do this well and you’ll hook people into reading further. Do this poorly and even the coolest, most significant results may go unread.

References

  • Bordage, G (2001) Reasons reviewers reject and accept manuscripts: The strengths and weaknesses in medical education reports. Academic Medicine 76(9): 889-893
  • Cetin, SA and DJ Hackam (2005) An approach to writing a scientific manuscript. J. Surgical Research 128: 165-167.
  • Day, RA and B Gastrel (2006) How to Write and Publish a Scientific Paper. Greenwood Press, Westport, CT.
  • Wells, W (2004) Me write pretty one day: How to write a good scientific paper. J. Cell Biol. 165(6): 757-758.

November 6, 2009 at 12:56 pm Leave a comment


Science of Scientific Writing

This article describes what readers expect when they read - and how scientific writing often violates those expectations.