Basically the difference between a null and alternative hypothesis is that the former contradicts the research question while the latter affirms it. A null hypothesis is a type of hypothesis used in statistics that proposes that no statistical significance exists in a set of given observations. Statistics 101 Null And Alternative Hypotheses Part 1 Linear Regression Hypothesis Regression An alternative and null hypothesis include statements with the same purpose of providing the researcher with a basic guideline. . On the contrary an alternative. A hypothesis is an approximate explanation that relates to the set of facts that can be tested by certain further investigations. The null and alternative hypotheses are two mutually exclusive statements about a population. The hypotheses are conjectures about a statistical model of the population which are based on a sample of the population. Its usefulness is sometimes challenged...