In article <[EMAIL PROTECTED]>,
Jerry Dallal <[EMAIL PROTECTED]> wrote:
> (1) statistical significance usually is unrelated to practice
> importance.
I don't think so. I can think of many examples in which statistical
inference plays an invaluable role in practical applications and
instrumentation, or indeed any "practical" application of a theory etc.
Not just in science, but engineering, e.g aircraft design, studying the
brain, electrical enginerring. Certainly there are examples of
statistical nonsense, e.g. polls, but i wouldn't go so far as to say it
is usually like this.
I *would* argue that without some method to determine the likelihood of
a difference b/w two conditions you have no chance of determining
practical importance at all.
> (2) absence of evidence is not evidence of absence
Everyone who has done elementary statistics is aware of this edict. But
what if your power is very high and/or you have very large N? I have
always found it surprising that we can't turn it around and develop a
probability that two groups are the same. Power or beta is surely
correlated with the certainty of this approach.
Chris
Sent via Deja.com http://www.deja.com/
Before you buy.
=================================================================
Instructions for joining and leaving this list and remarks about
the problem of INAPPROPRIATE MESSAGES are available at
http://jse.stat.ncsu.edu/
=================================================================
