Stating Hypotheses One common use of statistics is the testing of scientific hypotheses. First, the investigator forms a research hypothesis that states an expectation to be tested. Then the investigator derives a statement that is the opposite of the research hypothesis. This statement is called the null hypothesis (in notation: H0 ). It is the null hypothesis that is actually tested, not the research hypothesis. If the null hypothesis can be rejected, that is taken as evidence in favor of the research hypothesis (also called the alternative hypothesis, H a in notation). Because individual tests are rarely conclusive, it is usually not said that the research hypothesis has been “proved,” only that it has been supported. An example of a research hypothesis comparing two groups might be the following: Fourth-graders in Elmwood School perform differently in math than fourth-graders in Lancaster
This is the end of the preview. Sign up
access the rest of the document.