Basics and Descriptive Statistics
The study of statistics explores the collection, organization, analysis, and interpretation of numerical data. The concepts of statistics may be applied to a number of fields that include business, psychology, and agriculture. When the focus is on the bio-logical and health sciences, we use the term biostatistics.
How to determine the appropriate statistical test
- Specify the biological question you are asking.
- Put the question in the form of a biological null hypothesis and alternate hypothesis.
- Put the question in the form of a statistical null hypothesis and alternate hypothesis.
- Determine which variables are relevant to the question.
- Determine what kind of variable each one is.
- Design an experiment that controls or randomizes the confounding variables.
- Based on the number of variables, the kinds of variables, the expected fit to the parametric assumptions, and the hypothesis to be tested, choose the best statistical test to use.
- If possible, do a power analysis to determine a good sample size for the experiment.
- Do the experiment.
- Examine the data to see if it meets the assumptions of the statistical test you chose (primarily normality and homoscedasticity for tests of measurement variables). If it doesn't, choose a more appropriate test.
- Apply the statistical test you chose, and interpret the results.