Donald Burrill wrote: > > The null hypothesis is the one that permits you to define a sampling > distribution for the statistic you will observe. A disribution cannot > be specified for an hypothetical inequality: so the "null" hypothesis > is always the one that contains an equals sign (=).
This is a total misconception of what is going on. The presence of an equals sign has nothing to do with choosing the null hypothesis. Possibly the "professor" is under the same misapprehension. Where one-sided tests are concerned, the "real" null hypothesis is a composite one and the criticial point of the test statistic is chosen so that the probability of rejection satisfies a certain inequality for all point "null hypotheses" within the composite null hypothesis region (i.e. any given point null hypothesis is considered to be true and the probability of rejection is determined for this truth)... this leads to a point null hypothesis which is on the boundary effectively being the one which determines the critical point. As said in another post, the null hypothesis is the one which one is prepared to accept unless there is strong evidence to the contrary. David Jones . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
