The standard IMRaD format (Introduction, Methods, Results and Discussion) sets aside one section of a research paper for the results and another for discussing the results. Put simply, the two sections answer two different questions: the Results section answers the question ‘What’, whereas the Discussion section answers the question ‘So what’.
Results: answering the question ‘What’
The Results section is where the authors report their findings. This is the ‘hard’ product of the entire research, often serving as raw material for other research, reviews, meta-analyses, etc. The Results section is for hard facts; it is the most objective and data-intensive part of the paper but contains no comments or explanation of what the data imply. If the paper comprises multiple experiments, the Results section is organised in the same sequence as the Methods section, so that readers can see the appropriate results for each corresponding experiment.
It is also useful to remember that the Results section is:
(1) typically written using the simple past tense because you are merely reporting on what you found, and
(2) virtually free of citations because original findings are being reported, and therefore, no other sources are required.
Discussion: answering the question ‘So what’
Now that readers have the numbers, the author must say what those numbers mean, what their implications are, whether they conform to the expectations and thus support the initial hypothesis and so on. Whereas the structure of the Results section typically mirrors that of the Methods section, the Discussion section can take a thematic approach, presenting the author’s interpretation of the research problem. The Discussion section may use some text from the Results section, but that is mainly to jog the reader’s memory or to advance an argument.
The Discussion section also involves seeing the present work in the context of earlier work: whether the present findings corroborate those of the earlier researchers or contradict them; if the latter, the Discussion section needs to explain why. The Discussion section also allows the author to speculate on how the present findings can shape future research.
Remember, when writing the Discussion section, it should deliver on the promise made towards the end of the Introduction section, which spells out the exact objectives of the study. The Discussion section should show how the objectives have been met or fulfilled.
The Discussion section also differs from the Results section in that it:
(1) uses a mix of tenses: the past to refer to specific results reported in a specific study, the present to indicate the so-called ‘universal truths’ or accepted dogmas of the discipline and the future to speculate, and
(2) offers many citations referring to earlier work.
The combined Results and Discussion section
Some journals combine the two sections because that may work better in some disciplines, especially those not centred on actual experiments but on theories and interpretations, and in some papers comprising a series of different experiments, each meant to explore a distinct aspect of a study. For example, a paper devoted to examining the following can work better with a combined Results and Discussion section: different aspects of climate change such as mathematical models that attempt to predict the extent of changes in concentrations of greenhouse gases, the likely impacts of those changes and different measures to adapt to the changes when the impacts are adverse.