Null Hypothesis

Posted on November 13, 2009 by


Carl wants to know whether there is a difference in how fast men drive versus women. He’ll be using radar to clock the speed of every car that goes by for an hour and record whether the driver was a man or woman. In Null Hypothesis testing, the Null Hypothesis must be stated and the study results will lead to either rejecting the Null Hypothesis or not. The Null Hypothesis, symbolized H0, is that there will be no effect. In this case, the Null Hypothesis is that there will be no mean difference between the driving speed of men and the driving speed of women. Just as in America people are considered innocent until proven guilty, we consider that the Null Hypothesis is true unless the data is strong enough to suggest otherwise. After analyzing the data, the Null Hypothesis is either rejected or not. If Carl rejects the Null Hypothesis based on his data, then either men are driving significantly faster than women, or women are driving significantly faster than men.

Posted in: Six Sigma