6.1 Identify the population
The language of inference can change depending on the application, but most commonly, we refer to the things we cannot observe (but want to know about) as the population or as features of the population and the data that we observe as the sample. The goal is to use the sample to somehow make a statement about the population. In order to do this, we need to specify a few things.
Identifying the population is the most important task. If you cannot coherently identify or describe the population, then you cannot make an inference. Just stop. Once you’ve figured out what the population is and what feature of the population you want to make a statement about (e.g. the mean), then you can later translate that into a more specific statement using a formal statistical model (covered later in this book).