Hypothesis Test

Statisticians follow a formal process to determine whether to reject a null hypothesis, based on sample data. This process is called hypothesis testing. An hypothesis test consists of four steps.

• Formulate the hypotheses. This involves stating the null and alternative hypotheses. The hypotheses are stated in such a way that they are mutually exclusive. That is, if one is true, the other must be false; and vice versa.
  
  
• Identify the test statistic. This involves specifying the statistic (e.g., a mean score, proportion) that will be used to assess the validity of the null hypothesis.
  
  
• Formulate a decision rule. A decision rule is a procedure that the researcher uses to decide whether to reject the null hypothesis.
  
  
• Test the null hypothesis. Use the decision rule to evaluate the test statistic. If the statistic is consistent with the null hypothesis, you cannot reject the null hypothesis; otherwise, reject the null hypothesis.