4 Sample size calculations

By this point, you have learned how to:

• describe the target population and source population
• identify a suitable sampling frame
• select a robust sampling method to select sampling units (e.g. individual animals) from the sampling frame.

A crucial step in finalising your sample is to determine how many sampling units should be selected. In this section, we will need to introduce some statistical concepts, as we use statistical calculations to define the minimum required sample size. However, there are also non-statistical considerations, which we will review first.