As a working engineer and part time graduate student I do not even
understand why anyone would want to do away with hypothesis testing.
I have spent many, many hours of my graduate school life learning,
reading, calculating, and analyzing using hypothesis tests.
Hypothesis testing is not bad. It is errors in designing the
experiment that are bad and this comes from PEOPLE not the math. What
is the fuss? Are you guys telling me that all of this knowledge I am
being taught will be worthless? Come on, find something else to say....
In article <8dfphq$crm$[EMAIL PROTECTED]>,
[EMAIL PROTECTED] wrote:
> Response embedded within message:
>
> In article <[EMAIL PROTECTED]>,
> [EMAIL PROTECTED] wrote:
> >
> > The way this world is ---
> > A master's candidate, or a phD candidate, or a professor,
> > or a working scientist, has put a lot into his project.
> > In terms of time, in terms of money, and more important
> > still, in terms of emotional commitment, (S)he has lived
> > with this project for two years or more.
> >
> > That is a source of subjective bias: (S)he WANTS the data to
> > show something, preferably to support the original idea behind
> > the research, but even failing that, to show something.
> >
> > There needs be an objective brake on this wish. An hypothesis
> > test is that a brake. NOT rejecting the null hypothesis means
> > that the data has no information (about whatever aspect of the
> > data the test was designed to look at), STOP THERE; go no
> > further.
>
> I hope not to get too off topic here, but sometimes the failure to
> reject the null hypothesis has more implications than successfully
> rejecting it. I understand your point here, and certainly have seen it
> happen both personally and in the literature. However, as long as the
> experiment has a sufficient sample size to detect a meaningful effect
> (not necessarily just a null of an effect size of zero), then there is
> something to say. For example, the literature has been overflowing
with
> reports of "estrogenic compounds" such as DDT/DDE that affect sexual
> development of exposed animals. If someone found that DDE has little
> ability to competitively bind to estrogen receptors (which someone has
> found), at least to an extent necessary to elicit strong estrogenic
> activity, this would not only mean that the null hypothesis that DDE
is
> estrogenic was rejected, but that something ELSE must be happening;
ie.
> that the known alterations to sexual development after exposure to DDE
> is not due to estrogenic actvity. I am sure that this sort of thing
must
> be happening in other fields.
>
> >
> > Without some objective brake, the master's student, etc. will
> > go ahead to say something about the data, even when the test
> > would have told her(im) there is nothing to say.
>
> Failure to reject null hypotheses that have been "successfully
rejected"
> in numerous previous experiments, and thus are generally accepted by
the
> scientific community at large, can have big implications, even if the
> alternative explanations were not tested and thus remain unknown. It
may
> not happen often, but failure to reject a null hypothesis,
particularly
> one that was expected to be rejected, may indicate a poorly executed
> study, but it may signal that the underlying theory from which the
> experiment is based upon is wrong. That alone is valuable.
>
> Shane de Solla
> [EMAIL PROTECTED]
>
> <snip>
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
>
--
Charles Madewell
Interests: Engineering Management, Reliability Engineering,
Failure Modes Analysis, Design of Experiments, and
Statistical Analysis.
Sent via Deja.com http://www.deja.com/
Before you buy.
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