Jack Cohen [The Earth is Round (p < .05), American Psychologist, 1994, 49, 997-1003] made a distinction between a NULL hypothesis and a NIL hypothesis. The NULL hypothesis is that which is being directly tested. With the so-called "parametric" tests, this is the hypothesis that specifies an exact value for the tested parameter (such as mu = 10, mu <= 10, or mu >= 10) rather than not that (such as mu NE 10, mu > 10, or mu < 10). The NIL hypothesis is a null hypothesis that specifies a zero difference or zero effect, such as (mu1 - mu2) = 0, rho = 0, phi = 0, eta = 0, and so on. IMHO, NHST (null hypothesis statistical testing, also known as Statistical Hypothesis Inference Testing, SHIT -- Jack Cohen's wit) is most easy to defend when null hypotheses are not nil hypothesis but rather are a parametric prediction of the theoretical model being tested, for example, the proportion of items correctly recalled under the conditions employed in this experiment is .75.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Karl L. Wuensch, Department of Psychology, East Carolina University, Greenville NC 27858-4353 Voice: 252-328-4102 Fax: 252-328-6283 [EMAIL PROTECTED] http://core.ecu.edu/psyc/wuenschk/klw.htm -----Original Message----- From: Donald Burrill [mailto:[EMAIL PROTECTED] Sent: Wednesday, February 25, 2004 5:36 AM To: Phillip Good Cc: [EMAIL PROTECTED] Subject: Re: [edstat] null means null (Reply to OP and to edstat.) On Tue, 24 Feb 2004, Phillip Good wrote: > Null means null. One can hardly argue with that. Now, let me point out that one of the meanings of "null" is "zero". Are we to understand, Phillip, that you are arguing that the proper null hypothesis in the case under discussion is H0: P = 0 ? If this is what you mean, please show us how you would test it. I want to watch.... But perhaps this is not what you had in mind. (Hard to tell -- telepathy is not one of my skills.) . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
