define: null hypothesis
The null hypothesis (H 0) is a hypothesis which the researcher tries to disprove, reject or nullify. The 'null' often refers to the common view of something, while the alternative hypothesis is what the researcher really thinks is the cause of a phenomenon. The simplistic definition of the null is as the opposite of the alternative hypothesis, H 1, although the principle is a little more complex than that. The null hypothesis (H 0) is a hypothesis which the researcher tries to disprove, reject or nullify.