No one needs a theory as justification
for rotating a scatter plot. One ancient
suggestion, which seems to have been passed
on orally rather than written down, is to
recommend rotation of the printed page
before trying to make sense of a scatter plot.
It depends what you search for, or are sensitive to.
As Bland and Altman have pushed the idea very
hard in their medical statistics texts and in several
papers in medical/medical statistical journals, the
terminology Bland-Altman plots seems to have become
widely used in those areas. (As usual, I would be
astonished if either had invented that term.)
On the other hand, and crucially, those plotting
difference versus mean (or sum) in other fields
have not, so far as I am aware, felt that
the practice needed a special term, or even
special emphasis. Hence many examples are
probably half-buried in relevant literatures.
Nick
[email protected]
Hom, Willard
> Thank you for all of that information. I was primarily
> concerned that there was some underlying
> theory that limited this type of comparison to the
> health/medical field or to physical measurements
> by two mechanical (non-human) devices. When the literature
> about its use seemed to come only from
> one field, I began to wonder if I had missed something.
Nick Cox
> More generally, Bland-Altman plots are just
> special case of residual vs fitted plots,
> an idea with even longer roots. So after
> an appropriate -regress-, -rvfplot- is
> yet another way to do it.
>
> Other discussions of this area have appeared in
>
> 2004. Graphing agreement and disagreement.
> The Stata Journal 4: 329--349.
>
> and will appear in
>
> Assessing agreement of measurements and
> predictions in geomorphology. Geomorphology
> in press
>
> Nick
> [email protected]
>
> Nick Cox
> >
> > Recently I've realised that in adding some details
> > to -concord-, Tom Steichen and I have unwittingly
> > revisited territory surveyed by Paul Seed in STB-55.
> > As he in turn didn't quote our prior work from STB-43 this
> > may look like some sordid dispute, but in each
> > case no more than ignorance and oversight is to blame.
> >
> > Nick
> > [email protected]
> >
> > Hom, Willard
> >
> > > I'm wondering if anyone knows if it is appropriate to use the
> > > Bland-Altman approach (as implemented
> > > in STATA) for comparing the measurements from two separate
> > > rating mechanisms. That is, I'm checking
> > > whether two rating sytems that rate the same population of
> > > objects can be "tested" for their
> > > equivalence through the Bland-Altman method (plots, etc.).
> > >
> > > In my perusal of literature that mentions use of the
> > > Bland-Altman method, I have only seen its
> > > application in the comparison of two measurement devices that
> > > measure 'physical qualities" (as in
> > > medical/health research). Has anyone seen an application
> > > (and a defensible one) of the method in
> > > psychology, sociology, or economics, where there may be an
> > > interest in exploring the equivalence of
> > > two sets of ratings of the same objects/persons/constructs....
>
*
* For searches and help try:
* http://www.stata.com/support/faqs/res/findit.html
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
