Posted by
peter link on
Oct 27, 2006; 1:15am
URL: http://spssx-discussion.165.s1.nabble.com/Re-small-sample-repeated-predictors-more-tp1071739p1071742.html
I guess that is a possibility. If you used pre- as a covariate, and post-
as your dependent variable (ANCOVA). Again, sample size is small, which
concerns me. I guess you might try that. My one question would be
concerning your sample size. Maybe others on the list would have imput
about that.
I wouldn't suggest doing linear regression on a single individual using just
pre- and post. If you would do it this way, why not use all of the data
points, not just pre- and post-? That would make more sense to me.
I am curious about what you had done in this previous study with baseball
players. It seems like the way you approached this problem, you could make
inferences about specific players, but not about players in general.
Hopefully someone else will comment about your problem, also. I guess an
ANCOVA approach may be acceptable, though. Even though you throw away a lot
of data, it may be the best you can do, given such a small sample.
Peter Link
-----Original Message-----
From: SPSSX(r) Discussion [mailto:
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[hidden email]
Sent: Thursday, October 26, 2006 4:41 PM
To:
[hidden email]
Subject: Re: small sample-repeated predictors-more
In a message dated 10/26/2006 6:42:06 PM Eastern Standard Time,
[hidden email] writes:
Using some statistical techniques, such as linear regression is no longer
valid, due to you not having independent observations (within individual)
....What about linear regression based on scores of pre and post
observations in a single individual? I also ran multiple regression on data
from single
players, looking at how varying HRV on each measurement occasion (prior to
every at-bat) and it's effect on outcome (each at bat's result)? I then
compared pre and post with intervention differences in how HRV predicted
performance. This was done on every player in the line-up for the entire
season (over
140 measurement occasions pre and post).
__________________________________________
Roland A. Carlstedt, Ph.D.
Licensed Clinical Psychologist/Licensed Applied Psychologist
Clinical and Research Director: Integrative Psychological Services of NYC
Chair and Head Mentor: American Board of Sport Psychology
Research Fellow in Applied Neuroscience: Brain Resource Company
_www.americanboardofsportpsychology.org_
(
http://www.americanboardofsportpsychology.org/)
[hidden email]
917-680-3994