Understanding null hypothesis testing

One common way of structuring and processing these tests is to use null hypothesis testing. This represents a frequentist approach to statistical inference. This draws inferences based upon the frequencies or proportions in the data, paying attention to confidence intervals and error rates. Another approach is Bayesian inference, which focuses on degrees of belief, but we won't go into that in this chapter.

Frequentist inference has been very successful. Its use is assumed in many fields, such as the social sciences and biology. Its techniques are widely implemented in many libraries and software packages, and it's relatively easy to start using it. It's the approach we'll use in this chapter.

Understanding the process

To use the null hypothesis process, we should understand what we'll be doing at each step of the way. The following is the basic process that we'll work through in this chapter:

1. Formulate an initial hypothesis.

2. State the null (H₀) and alternative...