Guidelines for Writing a Laboratory Report.1
Aim.
Exactly what idea or principle did you set out to test or investigate? This should
be clearly stated in one or two lines.
Introduction.
It is a common mistake to try to include too much information in the introduction;
it is not meant to provide a review of the literature! Instead, it is designed to set the
experiment in context; it is designed, in short, to ‘introduce’ it. This means it should
be clear to the reader why one might do this particular experiment, i.e. why it is
sensible to try to test the idea presented in your aim? Some factors you might
consider are: 1) Will it help to establish the mechanism of action of the drug? 2) Is
the drug(s) clinically important or does it represent a clinically important class of
drugs? 3) Are you examining a clinically important class of receptor?
Methods.
The idea of writing an experimental method is two-fold. Firstly, given your
methods it should be possible for you, or anyone else, to exactly reproduce the
experiment (and hopefully the results), at a later date. For this to be possible all the
information that is important for ‘creating’ the results must be included. The second
thing that an accurate methods section allows is a critique of your approach. If
someone else believes that your method may have produced the wrong result, they
should be able to assess this from the details you provide. In addition, you should
keep in mind that your report describes what you did to obtain the results – this is
NOT the same as the laboratory script which tells the reader what ‘should be done’
during the practical. Even if you followed this script to the letter you should
normally use the past tense because you are talking about what you did. Quite often
you will also find that there were important things you were told in class that did not
appear on the script; it may well be important to include some of these.
(Occasionally, if the script provides all of the details for your Methods section, then
you might be asked to place it in an appendix.) Finally, try to keep in mind that you
need only provide details about steps which could change the experimental outcome
if they were not done in an identical fashion (i.e. there is no need to tabulate how
each drug concentration was worked out). As you write this section remember to
keep asking yourself, ‘if I changed this slightly, could it affect the experimental
outcome?’.
Results and Analysis.
First, you should present your data and ‘talk’ the reader through it (i.e., explain the
information you are showing). The presentation of graphs and the labelling of axes
etc. are important to get right. In addition, original records should always be
included (if these are very extensive an appendix may be used). Next, look at your
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© Dr Guy Moss
data! Do they seem reasonable? Are they broadly in line with what is to be expected
or are there any significant deviations? Are they suitable for the analysis you wish to
perform? What assumptions/criteria are essential to the analysis – are these met?
What can be calculated from the results? Have you performed an appropriate
statistical analysis and did you calculate errors where possible?
Discussion and Conclusions.
This section is designed to highlight the main points of your analysis, draw any
conclusions from the experiment and put the results into context. For example, as a
starting point, once you have given the rationale of your experiment (as you will
have done in your introduction) you may then wish to comment on whether or not
the goals of the experiment were met. However, you do not want to simply say ‘the
goals were met’ because this provides neither insight nor information. Instead, you
might conclude something such as ‘I have shown that atropine works by reversible
competitive inhibition’. Then you would probably want to discuss this fact. This
means setting your findings in a broader context. Some examples of the things you
might consider are: is this mechanism of action unique, or does it apply to other
drugs? Does it have implications clinically? Can any predictions be made and tested
from related theory? Are there any weaknesses to the data; does it really test the
model adequately? You may well find that you discuss ideas raised in the
introduction. This is perfectly alright but do not repeat your introduction. Also, as
for the introduction, do not review all the facts you can find about this topic/drug;
make sure the information is relevant i.e. that it relates quite specifically to your data.
If the experiment failed to answer the question, try to think of reasons why this
happened and how it could be improved next time. For example, is there an
alternative way to do things that might provide a clearer result?
Finally, at certain points it may be important to support statements in your
discussion with references. If so, then these should be included at the end of your
report and also cited in the text. You can look at any scientific paper to see the
style(s) used but the following example should give you the idea:
In the text “Some of the most important ideas in modern neuroscience stem from
work on the neuromuscular junction carried out at UCL (e.g. Fatt and Katz, 1952).”
Then in your references section:
Fatt, P. and Katz, B., (1952). Spontaneous subthreshold activity at motor nerve
endings. J. Physiol., Vol., 117(1), 109-128.
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In summary, a good practical account is often quite short but it should provide
original insight (i.e. your own thoughts, not just those in the practical script) and it
must be focussed!