The Scientific Paper:  Discussion

You should interpret your results in light of other published results, by adding additional information from sources you cited in the Introduction section as well as by introducing new sources. Make sure you provide accurate citations. 

Relate your discussion back to the objectives and questions you raised in the Introduction section. However, do not simply re-state the objectives. Make statements that synthesize all the evidence (including previous work and the current work). 

Do not make statements that are too broad:  it is unlikely, for example, that through one Rhizobium-legume experiment, you will discover that there is no symbiosis between the two organisms.  Limit your conclusions to those that your data can actually support, such as "We did not find a significant effect of Rhizobium inoculate on soybean biomass in this experiment."  You can then proceed to speculate on why this occurred and whether you expected this to occur, based on other workers' findings. 

Suggest future directions for research, new methods, explanations for deviations from previously published results, etc. 

If necessary, note problems with the methods and explain anomalies in the data. Do not simply list the problems but provide thoughtful discussion about the implications of the errors in terms of your conclusions.

How to Cite Sources in the Discussion Section

It is important to cite sources in the discussion section of your paper as evidence of the claims you are making. There are ways of citing sources in the text so that the reader can find the full reference in the literature cited section at the end of the paper, yet the flow of the reading is not badly interrupted. Below are some example of how this can be done:

"Smith (1983) found that N-fixing plants could be infected by several different species of Rhizobium."

"Walnut trees are known to be allelopathic (Smith 1949, Bond et al. 1955, Jones and Green 1963)."

"Although the presence of Rhizobium normally increases the growth of legumes (Nguyen 1987), the opposite effect has been observed (Washington 1999)."

Note that articles by one or two authors are always cited in the text using their last names. However, if there are more than two authors, the last name of the 1^st author is given followed by the abbreviation et al. which is Latin for "and others". 

The second citation (above) shows that it is acceptable, and encouraged, to cite more than one source for a particular statement.  This gives the statement more validity in its context and suggests that your research was thorough.  Note also that the three sources are ordered by publication date, so that the earliest citation comes first.

Make sure you give a full citation in the Literature Cited section for all sources mentioned in the text.

See examples of Discussion sections.

The Scientific Paper