I. Scientific Laboratory Report
Writing a laboratory report is like writing an original research
paper. The most common format for a scientific research paper
is:
Abstract
Introduction
Materials and Methods
Results
Discussion
References
Introduction
The "Introduction" of the report should explain why
the work was done. What were the objectives of the research? How
does the research help to fill a hole in our knowledge? The Introduction
should include a clear statement of the problem or question to
be addressed in the experiment. It is always helpful to put this
question into some context by stating why this is an important
question to be answered or why you found this to be a particularly
interesting question. Any background material that is particularly
relevant to the question should be included in this section.
Materials and Methods
The "Materials and Methods" section tells how
the work was done. What procedures were followed? What research
materials were used: the organism, special chemicals, instruments?
In some of the labs you will be doing, many of the procedures
are given in great detail in the handouts. It is not necessary
to retype these verbatim, but rather summarize them, and provide
details only about changes from the handout and about your individual
project. The most important feature of this section should be
to include enough detail in your description of how your experiment
was set up and run that anyone reading the Materials and Methods
could repeat your experiment.
Results
The "Results" section explains in words what
you found, the data that you generated, explained succintly in
the body of the report and presented in detail as tables or graphs.
The results section should be written so that any college student
could read the text to learn what you have done. For example,
you might use a paragraph to explain what is seen on a particular
graph; "... When the enzyme as soaked in sulfuric acid, it
produced no change in absorbance...." Do not make the common
mistake of saying, "We performed the experiment, see figures
1-4." That is too brief and does not convey to a novice what
you have done. When stating your results in the body of the text,
refer to your graphs and tables. Do not attempt to discuss the
interpretation of your data-this should be done in the "Discussion"
section. Each table and figure should be numbered sequentially
for easy reference in the text, and figures should have a brief
description called a legend, which provides the reader enough
information to know what you did to produce the data.
Discussion
The "Discussion" section typically includes your appraisal
of what your research means, including its success in meeting
the objectives stated in the introduction, and its significance
in advancing your knowledge of the subject. This is also the place
to explain discrepancies or difficulties with experiments, as
well as suggestions for future work. For example, if you had initially
known what you know now, how might you have changed your experiments?
Most importantly, the Discussion provides an opportunity to compare
your results with those of others. What previous information exists
that is relevant to your research? Do your results support or
supplement that information? Once again, when providing your interpretation
of the data, direct the reader to specific tables and graphs to
prove your point.
References
Finally, it is important to place your work in perspective with
the published work of other scientists. We will not have much
opportunity to use references in Introductory Biology, but you
should use the CBE style of citation as outlined in Chapter 8
of the reference guide book Online! using the name and
date format as shown here. (Narnack and Kleppinger, 1998)
II. Presentation of Results In Scientific Reports: Figures
and Tables
Data that have been collected need to be presented clearly and
succintly. As a result, two forms of presentation are most commonly
used in scientific papers and reports: figures and tables. Which
method to use depends somewhat on the data, but in general anything
that can be displayed pictorally (e.g. as a graph or diagram)
is more desirable, because the reader can immediately see the
trends in the data. In the paper itself, graphs are referred to
as "Figures", and are numbered sequentially in the order
of presentation (Figure 1, Figure 2, etc). Tables are also numbered
sequentially. Although figures and tables are often placed directly
into the middle of scientific papers, for simplicity you may include
them at the end of your lab report, with one figure or table per
page.
Graphs
Graphs can be made using the graphing program "Cricket Graph",
or similar programs. Remember to label each axes including units
of measurement and clearly identify the data you are displaying
(e.g. label each line in a graph). In addition, every graph must
have a short description below it to tell the reader some basic
information about that data and the way it was obtained; this
is known as a legend. The legend starts with the figure number,
followed by a one sentence title. The text of the legend should
be no more than one short paragraph and should be as brief as
possible. Following is an example of a graph with legend:
Figure 1. Regeneration of Chlamydomonas flagella as
a function of time. Flagella were removed from cells using
the pH shock method and allowed to regrow under constant light.
Each data point represents the averaged result of 20 individual
cells and the error bars represent the 95% confidence interval.
This graph was made using the statistical program Excel and graphed
with Cricket Graph. Notice how the axes are labelled, and the
figure is numbered and titled (bold type). The legend explains
how the data were obtained. Please also look at the sample scientific
papers posted in the lab as other examples of legends.
Technical Hint:
To put a graph and legend together on the computer, it is easiest
to first make your graph using "Cricket Graph", and
then make a copy of it by choosing the Edit menu, and then the
Copy Graph command. Now, open "Word", the word
processing program, and on the blank sheet you can paste your
graph by going to the Edit menu again, and choosing Paste.
Hit the return bar a couple of times and then you can start typing
below the graph.
NOTE: Once you have pasted the graph, you cannot alter the graph
itself in the word processing program. If you decide to alter
the size of the graph, or anything on the graph itself, you must
go back to the graph (or datasheet) in Cricket Graph.
Tables
Tables should be made using the same principles outlined for graphs,
though the format is different. Tables can be created with Word,
using tabs to create the different columns. Tables are numbered,
but this usually appears at the top of the table. The title can
either be on a separate line directly below the table number,
or can directly follow the table number:
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The legend usually appears directly under the title for tables,
and should contain the same information as described for graphs.
The reason it is under the title is because footnotes are often
used for columns, and these are placed directly below the data.
Of course, all column headings should be clearly labeled as to
what data are listed below them.
© Copyright 2000 Department of Biology,
Davidson College, Davidson, NC 28036
Send comments, questions, and suggestions to: macampbell@davidson.edu