Reporting Statistical Results in Your Paper [Table of Contents] | Overview | Descriptive Statistics | Inferential Statistics | Overview
The results of your statistical analyses help you to understand the outcome of your study, e.g., whether or not some variable has an effect, whether variables are related, whether differences among groups of observations are the same or different, etc. Statistics are tools of science, not an end unto themselves. Statistics should be used to substantiate your findings and help you to say objectively when you have significant results. Therefore, when reporting the statistical outcomes relevant to your study, subordinate them to the actual biological results.
Reporting Descriptive (Summary) Statistics
Means: Always report the mean (average value) along with a measure of variablility (standard deviation(s) or standard error of the mean ). Two common ways to express the mean and variability are shown below:
"Total length of brown trout (n=128) averaged 34.4 cm (s = 12.4 cm) in May, 1994, samples from Sebago Lake."
s = standard deviation (this format is preferred by Huth and others, 1994)
"Total length of brown trout (n=128) averaged 34.4 ±12.4 cm in May, 1994, samples from Sebago Lake."
This style necessitates specifically saying in the Methods what measure of variability is reported with the mean.
Frequencies: Frequency data should be summarized in the text with appropriate measures such as percents, proportions, or ratios.
"During the fall turnover period, an estimated 47% of brown trout and 24% of brook trout were concentrated in the deepest parts of the lake (Table 3)."
Reporting Results of Inferential Tests
In this example, the key result is shown in blue and the statistical result, which substantiates the finding, is in red.
"Mean total length of brown trout in Sebago Lake increased significantly (3.8 cm) between May (34.4 cm ±12.4 cm, n=128) and September, 1994, (38.2 cm ±11.7 cm, n=114; twosample t-test, p < 0.001)."
NOTE: AVOID writing whole sentences which simply say what test you used to analyze a result followed by another giving the result. This wastes precious words (economy!!) and unnecessarily increases you paper's length.
Modified 9-12-02
Department of Biology, Bates College, Lewiston, ME 04240