Dear morphometricians,
many thanks to all those who either in emails directly to me or to
morphmet contributed to this discussion.
It was very interesting and instructive.
I have a lot of sympathy for Ian's point about what to do when one uses
an ANCOVA to test slopes and finds that it is sign
/<http://www.public.iastate.edu/~dcadams/>
phone: 515-294-3834
-Original Message-
From: andrea cardini [mailto:alcard...@gmail.com]
Sent: Thursday, March 24, 2016 12:01 PM
To: morphmet@morphometrics.org<mailto:morphmet@morphometrics.org>
Subject: [MORPHMET] using regression residuals for other
These complicated issues aside, there is a simpler reason not to use a
residual from a regression as the basis for further analyses. If two
characters are under natural selection based on some combination -- such as
selection on a ratio between them -- then the current value of character Y
is a re
Just as a quick follow up (and clarifications).
I recognize that there are already a number of methods to deal with these
well known issues (McCoy et al. 2006, Klingenberg 1996, Burnaby 1966,
etc..) and they may be better ways still. However, since the "using
residuals from a pooled within-group
Dean and Andrea,
I wanted to follow up on what Dean wrote regarding using residuals from a
pooled within-group regression, and what I think may be important
discussion that follows from it. Considerable research has gone into
investigating this issue, and as Dean points out, most of the time it i
[mailto:alcard...@gmail.com]
Sent: Thursday, March 24, 2016 12:01 PM
To: morphmet@morphometrics.org
Subject: [MORPHMET] using regression residuals for other analyses
Dear All,
this is something that, I believe, has already come up in the past.
However, I'd like to check it again.
What are the issues
Dear All,
this is something that, I believe, has already come up in the past.
However, I'd like to check it again.
What are the issues with, say, regressing shape on size, saving
residuals and using those in further analyses (e.g., other regressions
or testing group differences etc.)?
I sus
