The idea of a table is basically the same as a graph: to give a quick and interpretable presentation of a set of experimentally acquired data that shows trends. As in the case of the graph, the table should be able to stand on its own, be a presentation in itself.
1) Do not put into a table that which can be
effectively graphed! In general, tables are for comparisons,
single curved graphs are used to show trends, and multiple curved
graphs are used for the comparison of trends.
2) Give a concise and clear title/legend describing
the table. Any details of the experiment that might have
influences on the results must be mentioned. Questions that a
reader might ask such as when, where, what, and how must be answered.
On the other hand, for purposes of conciseness and neatness do
not present details that would have no value in interpretation
of the data. A legend should make clear the answers to these questions:
What? (e.g., penguins); How? (e.g., using a treadmill);
What conditions? (e.g., 0 °C in the dark). If
certain details are written elsewhere, it is legitimate to guide
the reader to those details rather than rewriting them (e.g.,
phrases such as "see experimental protocol on Photosynthesis
handout for details" or "see materials and methods"
are appropriate phrases.)
3) Often the primary function of a table is to allow
the reader to easily make comparisons. Arrange and order
the table such that the reader's eyes flow easily between the
data that need to be compared.
4) If repeated data points were taken for each set
of given conditions (as is necessary for good science), then the
average of these points should be presented along with some
indication of the spread of the data (often the standard
deviation).
4. Indicate the units of any measurement,
but put them only in the legend, column headings, or row headings.
It is very messy (and a lot of unneeded work) to put the units
after every number.
5. Put in the first column that which you control
(like the x-axis on a graph) and put in the adjacent columns that
which you measure (like the y-axis on a graph).
6. Do not claim more significant figures than you can justify. Just because your calculator goes out to 10 or so places, don't blindly copy what it reads. If you tell someone your car goes 89.56787 miles per hour, that implies you can have measured it to that accuracy! Most biological data can only be measured to three or two significant numbers.
Legend examples:
1. pH versus substrate concentration:
Comment: Poor because
it repeats what is probably already in the table; does not tell
us what organism or system, how any measurements
were made, the reaction medium, ...
2. Table of Laboratory measurements done with tubes
5, 8 and 10 with Mary in room 201 science while listening to 1950's
rock-n-roll. We dropped the third tube, but we repeated it, so
that data are not included. The TA told us a funny joke about
cantaloupes and antelopes.
Comment: Poor because
it has too much irrelevant babble.
3. The average speed (m/sec) cats move toward a particular
brand of cat food. The speed is an average ± S.D. of ten
different 2 year old male cats that have not been fed for 18 hours
prior to the experiment. The food is placed 10 feet form each
cat. The time from when the food is exposed to the point when
they are within 5 feet of the food is measured with a stop watch.
The ten different brands were offered in the order indicated on
ten successive days, always at 8 a.m. 25°C. See methods
section for other details.
Comment: Good becasue
it tells: How the experiment was done, what was
involved, and other relevant information is reported. They do
not bother to repeat what is already printed elsewhere, but they
do direct you as to where to find that information.
Table examples:
Poor:
Improved:
Silly order. We are obviously interested in the most popular color, therefore order them that way.
| blue | 12 |
| green | 54 |
| yellow | 2 |
| orange | 4 |
| white | 71 |
| cantaloupe | 98 |
| cantaloupe | |
| white | |
| green | |
| blue | |
| orange | |
| yellow |
Poor: Improved:
Mixed units and unit labels after each number make the table a real chore to read. Too many significant figures are claimed in many cases. Finally, this data would be better presented in a plot in order to see the relationship of age and rate. Obviously, we also need a legend so that we know what 'age' and 'rate' mean and how they were obtained
| Age | Rate |
| 200 days | 12m/min |
| 250 days | 13.6543 m/min |
| 0.84 yrs. | 42 km/hr |
| 1.11234 yrs | 44 km/hr |
| 3 generations | 103 km/hr |
| 5 yrs | 105 km/hr |
|
|
The following are taken from journal articles. Note that you have a good understanding of what is happening without reading the article.