Just as the introduction and methods sections can sometimes be blurred when writing the thesis, especially when aspects of the field site are of prime importance to the study, it can also be difficult to work out what should go in your results and discussion sections. This is especially so when you have a complex dataset, the experiment(s) encountered problems, or the results of one part of the study inform the next part of the study. The basic rules to follow are:

• The results section should only contain results! Obvious? Perhaps! This means NO interpretation of results; don’t be tempted to run straight from a statement of the significance of a test into something like ‘suggesting that individuals in population X are more vulnerable to Y predators’. You don’t want to give away the ending!
• In a neat reversal, the discussion section should not contain results! What does this mean? NO numerical or graphical results (e.g. means with standard errors, P values), and NO new outcomes that haven’t been introduced in previous sections.

Have a look at the following phrases and work out whether they belong in a results section or a discussion section.

1. ‘Important differences were evident in the patterns of mortality among the studied species. The Acropora had high rates of whole-colony mortality and little partial mortality. In contrast, rates of whole-colony mortality were low in Platygyra daedalea and Porites lobata.’
2. ‘The power to detect an 80% change in density between treatments was high for Diplosoma literianum, didemnids, Pyura stolonifera, Tricellaria porter and serpulid polychaetes (>0.8; Table 1).’
3. ‘Damaged colonies were consistently smaller than the controls across the entire experiment, and at the final census, this effect was statistically significant (Table 1; Fig. 3a).’
4. ‘It appears that colonies that originate from larger larvae have a selective advantage when mortality is low and occurs early in post-metamorphic life’.

Of course, this is easier to do in a hypothetical exercise than in the reality of thesis-writing, when you might have difficulty teasing out the outcomes and the implications of research that you’ve been so intimately involved with. Communication and revision with your advisor and mentor on what’s appropriate to include in each section will be important.
If you are contemplating publication of your study, bear in mind that some journals, particularly those with extreme space limitations – generally high-profile journals such as Nature, Science, Ecology Letters and others – will require authors to submit a combined results and discussion section. After working so hard to keep your results and interpretation in defined sections, it can be extremely difficult to integrate them into one section! Doing so usually requires some creativity and flair, which are really important in scientific communication, even if the public may not think of us as creative!

Let us us this example.