Re: ANOVA QUESTION - Terminology


Richard Ulrich wrote:
Reef Fish Bob has offered several inappropriate comments
to this question, not to mention the insults aimed at me -

On 9 Sep 2006 17:28:52 -0700, "Reef Fish"
<Large_Nassau_Gr0uper@xxxxxxxxx> wrote:


Richard Ulrich wrote:
On 9 Sep 2006 12:53:19 -0700, "jp" <jpopovich@xxxxxxxxx> wrote:

I have the following set up:

One group (males, females)
One dependent variable (test scores), but tested pre and post tutoring.

Would this be a repeated measures design?

It can be analyzed that way, with the two periods.
RF >
The two periods are pre-tutor score and post-tutor scores and
it has only ONE variable, of the "difference" (improvement).

Depending on design, the "improvement" can be effectively
measured as the raw change score or difference; the regressed
change score (in the ANCOVA); or the simple outcome score
(rarely).





What would this be called (i.e., One-way ANOVA with repeated measures,
Two-way, etc.)?

For Pre-Post, the testing usually assumes that the group means do
not differ at Pre;
RF >
Why? Where did you get that?

That is sound advice which is offered in every course or text in
experimental design. Bob is apparently over his head here.

And just how many of those courses have you TAKEN, not to have
known anything about Linear Models at the Neter et al level?

I have TAUGHT Graduate level courses in Linear Models from
books of Graybill and others, on experimental designs from several
graduate level textbooks such as one by Cuthbert Daniels, not
household name in statistics, but known by anyone who knows
much of anything about experiment design and and the analysis
of data based on those designs -- as follow-up courses to my
graduate level course in Data Analysis which has Neter et al's book
as prerequisite which Richard Ulrich had never reached the level.

Need I say more?


and the efficient test is usually the one-way
ANCOVA, using the Pre as covariate.
RF >
That's just a simple T-test for two independent groups on the
DIFFERENCE of the pre-and-post scores. Freshman/sophomore
stuff, Richard.

Simple change is *not* the same as regressed change.
Reef Fish Bob seems to have missed a course.

That is only because your own deficiency to realize that the
regression approach (if you knew HOW) to linear models and
experimental design accomplishes the same thing that are
much more clumsily done WITHOUT the use of Linear Models.


jp, get you an elementary testbook on testing means.

That may save you much time in unlearning some bad advice you
get from these newsgroups.

-- Reef Fish Bob.

-- Reef Fish Bob.

.