Students often have difficulty writing the Conclusion of a paper because of concerns with redundancy and about introducing new ideas at the end of the paper. While both are valid concerns, summary and looking forward (or showing future directions for the work done in the paper) are actually functions of the conclusion. The problems then become:

  1. How to summarize without being completely redundant
  2. How to look beyond the paper without jumping completely in a different direction

1. Summary: Since the conclusion’s job is to summarize the paper, some redundancy is necessary. However, you are summarizing the paper for a reader who had read the introduction and the body of the report already, and should already have a strong sense of key concepts. Your conclusion, then, is for a more informed reader and should look quite different than the introduction.

In a report on bone tissue engineering, your introduction (see Online Handbook / Components of Documents / Introductions) and literature reviews (see Online Handbook / Components of Documents / Literature Reviews) might discuss osteoporosis, along with current methods of treatment and their limitations at length, since this involves developing context and establishing the gap for your paper. It would even likely form a large part of the literature review. Your conclusion, however, might summarize all of this in one sentence, while identifying itself as summary (by virtue of the “as mentioned previously”):

As mentioned previously, current treatments for osteoporosis that attempt to stimulate re-growth of bone are limited because of problems delivering appropriate signaling mechanisms.

A sentence like this in the introduction would create difficulty for most readers – who would not initially know what signaling mechanisms are or what role the play in process for bone growth. But by time they reach the conclusion, the audience should know what they are, as well as the problems with current mechanisms. The above sentence might not work anywhere else in the paper – since it relies on knowledge developed throughout the paper.

Similarly, since you”ve probably spent a fair amount of time and evaluating the solution in the body of the report, a simple reference to the technology is sufficient.

Techniques involving injecting nanoparticles containing bone growth factors at the relevant areas have been shown to be effective, safe, and stable [1,2, 8-10].

This sentence relies on the audience knowing that “effectiveness,” “safety,” and “stability” are the three criteria for a successful delivery method, and also what the terms mean.

These two sentences could form the basis of your conclusion: they review the key elements of an engineering paper (see Accurate Documentation / Conducting and Understanding Research in Engineering) by going over the situation-problem-solution-evaluation structure very briefly.

The summary could be longer. It might, for example, acknowledge the limitations of this method in current research:

However, research on the use of nanoparticles has yet to be conduct in vivo (in any applications) and bone tissue engineering is still in its infancy as a field of science.

Or, the conclusion might develop any of the above aspects in greater detail. The level of detail you engage in your summary is up to you – a conclusion can be as short as a few sentences and as long as several pages – depending on the length of the paper and the complexity of the subject matter. Prescribing a length for the conclusion is difficult, but it should not exceed 10% of the document itself, and in many cases is significant shorter.

One final note on summarizing your own writing: avoid copying and pasting sentences from the introduction or other parts of your paper into the conclusion. They won’t fit together appropriately because they were taken from a different context, and readers have a knack for spotting duplicated sentences.

2. Looking Forward: The other role of the conclusion in a scientific paper is, in fact, to introduce new avenues of potential study or to explain the potential impacts of your conclusions. This is almost an expectation in scientific papers. It should not, however, be seen as an opportunity to develop these avenues in significant detail, and should be clearly linked to the work described in your paper. In the above example, one might conclude with the following statement:

As researchers conduct more research into nanoparticles for use in drug delivery systems and bone tissue engineering matures as a field, the potential for finding a cure for osteoporosis increases. Specifically, work on matching growth factors with types of nanoparticle compounds and ways of controlling the release of these factors over time should, in the near future, turn bone tissue engineering from a field of research to an actual treatment method.

The final sentence should provide a strong take away statement that allows the audience to remember the main point of the paper – in the above example, the potential for a cure for bone disease and the work that needs to be done to achieve it.

Conclusion: In summary, the two main problems students encounter in writing conclusions are related to the two main functions of that component of a document. In summarizing the paper, the conclusion will exhibit some redundancy: the key is to aim this summary at readers who have read your report. In developing other avenues of study or application, the conclusion may have to introduce new ideas: the key here is to clearly relate these new applications or directions to the content of your report.