[R] two questions
Iasonas Lamprianou
lamprianou at yahoo.com
Thu Sep 9 09:23:04 CEST 2010
This sounds interesting, thank you. I'll have a look.
jason
Dr. Iasonas Lamprianou
Assistant Professor (Educational Research and Evaluation)
Department of Education Sciences
European University-Cyprus
P.O. Box 22006
1516 Nicosia
Cyprus
Tel.: +357-22-713178
Fax: +357-22-590539
Honorary Research Fellow
Department of Education
The University of Manchester
Oxford Road, Manchester M13 9PL, UK
Tel. 0044 161 275 3485
iasonas.lamprianou at manchester.ac.uk
--- On Wed, 8/9/10, Greg Snow <Greg.Snow at imail.org> wrote:
> From: Greg Snow <Greg.Snow at imail.org>
> Subject: RE: [R] two questions
> To: "Iasonas Lamprianou" <lamprianou at yahoo.com>, "juan xiong" <xiongjuan2000 at gmail.com>, "Dennis Murphy" <djmuser at gmail.com>
> Cc: "r-help at r-project.org" <r-help at r-project.org>
> Date: Wednesday, 8 September, 2010, 17:41
> Have you considered doing a
> permutation test on the interaction?
>
> Here is an article that gives the general procedure for a
> couple of algorithms and a comparison of how well they do:
>
> Anderson, Marti J and Legendre, Pierre; An Empirical
> Comparison of Permutation Methods for Tests of Partial
> Regression Coefficients in a Linear Model. J. Statist.
> Comput. Simul., 1999, vol 62, pp. 271-303.
>
> --
> Gregory (Greg) L. Snow Ph.D.
> Statistical Data Center
> Intermountain Healthcare
> greg.snow at imail.org
> 801.408.8111
>
>
> > -----Original Message-----
> > From: r-help-bounces at r-project.org
> [mailto:r-help-bounces at r-
> > project.org] On Behalf Of Iasonas Lamprianou
> > Sent: Tuesday, September 07, 2010 12:25 AM
> > To: juan xiong; Dennis Murphy
> > Cc: r-help at r-project.org
> > Subject: Re: [R] two questions
> >
> > By the way, ordinal regression would require huge
> datasets because my
> > dependent variable has around 20 different
> responses... but again, one
> > might say that with so many ordinal responses, it is
> as if we have a
> > linear/interval variable, right? I just hoped that
> there would be a
> > two-way kruskal-wallis or something like that. On the
> other hand, what
> > is going to happen if I (1) bootstrap data from all
> cells of my design
> > and average the rank ordering of the data of every
> cell? And then (2)
> > do the same but using data from a uniform/normal
> distribution so that I
> > assume that there is no difference between the cells?
> From point (1) I
> > will find the statistical value and from point (2) the
> expectation and
> > then with a third step (3) I can run a chi-square on
> the
> > observed/expected values. Would this be reasonable?
> But again, how can
> > I distinguish between main and interaction effects?
> >
> > Dr. Iasonas Lamprianou
> >
> >
> >
> >
> >
> > Assistant Professor (Educational Research and
> Evaluation)
> >
> > Department of Education Sciences
> >
> > European University-Cyprus
> >
> > P.O. Box 22006
> >
> > 1516 Nicosia
> >
> > Cyprus
> >
> > Tel.: +357-22-713178
> >
> > Fax: +357-22-590539
> >
> >
> >
> >
> >
> > Honorary Research Fellow
> >
> > Department of Education
> >
> > The University of Manchester
> >
> > Oxford Road, Manchester M13 9PL, UK
> >
> > Tel. 0044 161 275 3485
> >
> > iasonas.lamprianou at manchester.ac.uk
> >
> > --- On Tue, 7/9/10, Dennis Murphy <djmuser at gmail.com>
> wrote:
> >
> > From: Dennis Murphy <djmuser at gmail.com>
> > Subject: Re: [R] two questions
> > To: "juan xiong" <xiongjuan2000 at gmail.com>
> > Cc: "David Winsemius" <dwinsemius at comcast.net>,
> r-help at r-project.org,
> > "Iasonas Lamprianou" <lamprianou at yahoo.com>
> > Date: Tuesday, 7 September, 2010, 4:47
> >
> > Hi:
> >
> > On Mon, Sep 6, 2010 at 5:26 PM, juan xiong <xiongjuan2000 at gmail.com>
> > wrote:
> >
> > Maybe Friedman test
> >
> > The Friedman test corresponds to randomized complete
> block designs, not
> > general two-way classifications. David's advice is
> sound, but also
> > investigate proportional odds models (e.g., lrm in
> Prof. Harrell's rms
> > package) in case the 'usual' approach comes up short.
> It would be
> > helpful to know the number of response categories and
> some idea of the
> > number of cities-of-birth under study, though...
> >
> >
> > HTH,
> > Dennis
> >
> >
> >
> >
> > On Mon, Sep 6, 2010 at 4:47 PM, David Winsemius
> > <dwinsemius at comcast.net>wrote:
> >
> >
> >
> > > The usual least-squares methods are fairly robust
> to departures from
> >
> > > normality. Furthermore, it is the residuals that
> are assumed to be
> > normally
> >
> > > distributed (not the marginal distributions that
> you are probably
> > looking
> >
> > > at) , so it does not sound as though you have yet
> examined the data
> >
> > > properly. Tell us what the descriptive stats (say
> the means,
> > variance, 10th
> >
> > > and 90th percentiles) are on the residuals within
> cells cross-
> > classified by
> >
> > > the gender and city-of-birth variables (say the
> means, variance, 10th
> > and
> >
> > > 90th percentiles).
> >
> > >
> >
> > >
> >
> > > On Sep 6, 2010, at 4:34 PM, Iasonas Lamprianou
> wrote:
> >
> > >
> >
> > >
> >
> > >> Dear friends, two questions
> >
> > >>
> >
> > >> (1) does anyone know if there are any
> non-parametric equivalents of
> > the
> >
> > >> two-way ANOVA in R? I have an ordinal
> non-normally distributed
> > dependent
> >
> > >> variable and two factors (gender and city of
> birth). Normally, one
> > would try
> >
> > >> a two-way anova, but if R has any
> non-parametric equivalents, that
> > might be
> >
> > >> great.
> >
> > >>
> >
> > >
> >
> > > There is an entire task view page on robust
> methods if you decide to
> > press
> >
> > > on with this quest.
> >
> > >
> >
> > >
> >
> > > (2) Also, if the interaction of gender and city
> of birth is
> > statistically
> >
> > >> significant, which post-hoc tests should I
> run?
> >
> > >>
> >
> > >
> >
> > > How many cities are we talking about?
> >
> > >
> >
> > >
> >
> > > Thanks
> >
> > >>
> >
> > >> Jason
> >
> > >>
> >
> > >>
> >
> > >> Dr. Iasonas Lamprianou
> >
> > >>
> >
> > >
> >
> > > --
> >
> > >
> >
> > > David Winsemius, MD
> >
> > > West Hartford, CT
> >
> > >
> >
> > >
> >
> > > ______________________________________________
> >
> > > R-help at r-project.org
> mailing list
> >
> > > https://stat.ethz.ch/mailman/listinfo/r-help
> >
> > > PLEASE do read the posting guide
> >
> > > http://www.R-project.org/posting-guide.html
> >
> > > and provide commented, minimal, self-contained,
> reproducible code.
> >
> > >
> >
> >
> >
> > [[alternative HTML version deleted]]
> >
> >
> >
> > ______________________________________________
> >
> > R-help at r-project.org
> mailing list
> >
> > https://stat.ethz.ch/mailman/listinfo/r-help
> >
> > PLEASE do read the posting guide http://www.R-project.org/posting-
> > guide.html
> >
> > and provide commented, minimal, self-contained,
> reproducible code.
> >
> >
> >
> >
> >
> >
> >
> > [[alternative HTML version
> deleted]]
>
>
More information about the R-help
mailing list