Re: ANOVA QUESTION - Terminology

If you perform a t-test on the change (difference from pre and post)
don't you have to look at the initial scores to see if they were
different?

I was really more concerned with the terminology. Say I wanted to
compare the same dependent variable (pre and post scores), and I have
one independent variable (Group- A, B, C). I can see if I use the
differences between the pre and post this would be a simple one-way
with repeated measures. Assuming I don't use the differences what
would this be called, a two-way? That is, treating Group and Score as
independent variables?

Thanks for the responses!

Reef Fish 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.

The two periods are pre-tutor score and post-tutor scores and
it has only ONE variable, of the "difference" (improvement).


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;

Why? Where did you get that?

and the efficient test is usually the one-way
ANCOVA, using the Pre as covariate.

That's just a simple T-test for two independent groups on the
DIFFERENCE of the pre-and-post scores. Freshman/sophomore
stuff, Richard.

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.



For the repeated measures, it is "one-way" ANOVA with repeated
measures.

In general, a repeated-measures analysis with several
periods might have a few 'missings' and you could do
the closest thing to the same analysis by doing a two-way
ANOVA with Period and Subject (or ID) as the factors.


--
Rich Ulrich, wpilib@xxxxxxxx
http://www.pitt.edu/~wpilib/index.html

.

Relevant Pages

  • Re: ANOVA QUESTION - Terminology
    ... I know two groups is t-test and more than two is ANOVA. ... Most examples of ANOVA are 3 groups of race ... and Test# could serve as two independent variables, ... a repeated-measures analysis with several ...
    (sci.stat.consult)
  • Re: ANOVA QUESTION - Terminology
    ... MEANS is called, strangely, the ANOVA. ... -- Reef Fish Bob. ... a repeated-measures analysis with several ...
    (sci.stat.consult)
  • Relationship investigation with large dataset
    ... I want to investigate the relationship between 6 independent variables ... The p-values of 30 multivariate ANOVA tests are used in a T-test to ...
    (sci.stat.math)