12.1: What to Expect

In John Locke's An Essay Concerning Human Understanding, he suggests that few things in the world are known certainly to be true, but that we need to act based on the probability that something is true (Russell 2013). This line of reasoning is somewhat like the formal construction of what are known as statistical hypothesis tests and confidence intervals, though the specific interpretation of probability is somewhat different—essentially, the truth of a hypothesis about a social justice issue compared to evidence that is gathered from data observed from a sample. If there is enough evidence against the hypothesis, the hypothesis is abandoned as false; otherwise we conclude that sufficient evidence against the hypothesis was not observed. In this chapter we will first consider how statisticians construct hypotheses in a way that can be used within the formal framework required by statistical theory. 

By the end of this chapter, you will be able to: 

1. Define and discuss the concept of a hypothesis in the context of the parameters of a population. 
2. Be able to define and identify the null and alternative hypotheses in the context of an empirical investigation.  
3. Discuss the structure of looking for evidence in observed data for and against hypotheses. 
4. Interpret rejecting and failing to reject a hypothesis.  
5. Interpret significance levels and observed significance levels.  
6. Interpret confidence intervals.  

---