[R] ordinal variables

Fri Jun 4 13:34:05 CEST 2010

This is valuable material, thanks for all the help. I'll need many days to go through this information

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 Fri, 4/6/10, Joris Meys <jorismeys at gmail.com> wrote:

> From: Joris Meys <jorismeys at gmail.com>
> Subject: Re: [R] ordinal variables
> To: "Iasonas Lamprianou" <lamprianou at yahoo.com>
> Cc: r-help at r-project.org
> Date: Friday, 4 June, 2010, 11:24
> Hi,
> 
> If you look around a bit, there is some great material on
> the web
> about the powers and quirks of R. I've taught myself most
> of what I
> know from R through reading a lot and trying it out on the
> console.
> The help list is also a darn fine source of efficient code
> for a set
> of general problems.
> 
> It won't help any more this year, but I'm working on a
> guide for R to
> bundle valuable information I got from the help list and
> the internet.
> It should be ready in a couple of months, and it will be
> available for
> all to use. In any case, Owen's guide is of great value for
> an
> introduction to the command line and basic statistics:
> http://cran.r-project.org/doc/contrib/Owen-TheRGuide.pdf
> 
> Also the introduction to R is a must-read for all our
> students :
> http://cran.r-project.org/doc/manuals/R-intro.pdf
> 
> Next to that, a couple of websites are great additional
> sources of code :
> Quick-R, a guide for those who come over from
> SAS/SPSS/Stata. It
> contains tons of examples for statistical analyses in about
> every
> field. If you didn't know it yet, you'll love it for sure
> :
> http://www.statmethods.net/
> 
> The R graph gallery, to show what exactly can be done with
> the
> graphical power of R :
> http://addictedtor.free.fr/graphiques/
> 
> The R Graphics gallery, doing the same :
> http://research.stowers-institute.org/efg/R/
> 
> There's many more to be found, a whole community of users
> is
> contributing to the information in various ways. We give
> the sources
> mentioned here to our students, with the message that they
> should
> never underestimate the power of Google.
> 
> Last but not least, there is a specific mailing list
> regarding
> teaching statistics using R:
> https://stat.ethz.ch/mailman/listinfo/r-sig-teaching
> 
> You might want to take a look at their archives as well.
> 
> Cheers
> Joris
> 
> On Fri, Jun 4, 2010 at 6:39 AM, Iasonas Lamprianou <lamprianou at yahoo.com>
> wrote:
> > Thanks, I'll have a go and will let you know. I guess
> that the success has to do with how efficiently I help them
> to demonstrate the efficiency of code over menues. So part
> of the issue is how I teach them as well...
> >
> >
> > 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 Thu, 3/6/10, S Ellison <S.Ellison at lgc.co.uk>
> wrote:
> >
> >> From: S Ellison <S.Ellison at lgc.co.uk>
> >> Subject: Re: [R] ordinal variables
> >> To: "Joris Meys" <jorismeys at gmail.com>,
> "Iasonas Lamprianou" <lamprianou at yahoo.com>
> >> Cc: r-help at r-project.org
> >> Date: Thursday, 3 June, 2010, 15:44
> >> If you set them a problem that has
> >> them doing the same sort of thing
> >> five times and compare the time it takes with code
> pasted
> >> from an editor
> >> (eg Tinn-R) and the time it takes via menius, you
> may have
> >> more luck
> >> convincing them.
> >>
> >> A command line sequence is harder than menus the
> first two
> >> times but
> >> easier for any n iterations thereafter.
> >>
> >> Steve ellison
> >>
> >> >>> Iasonas Lamprianou <lamprianou at yahoo.com>
> >> 03/06/2010 14:51 >>>
> >> Thank you Joris,
> >> I'll have a look into the commands you sent me.
> They look
> >> convincing. I
> >> hope my students will also see them in a positive
> way
> >> (although I can
> >> force them to pretend that they have a positive
> attitude)!
> >>
> >> 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 Thu, 3/6/10, Joris Meys <jorismeys at gmail.com>
> >> wrote:
> >>
> >> From: Joris Meys <jorismeys at gmail.com>
> >> Subject: Re: [R] ordinal variables
> >> To: "Iasonas Lamprianou" <lamprianou at yahoo.com>
> >> Cc: r-help at r-project.org
> >>
> >> Date: Thursday, 3 June, 2010, 14:35
> >>
> >> see ?factor and ?as.factor. On ordered factors you
> can
> >> technically do a
> >> spearman without problem, apart from the fact that
> a
> >> spearman test by
> >> definition cannot give exact p-values with ties
> present.
> >>
> >> x <-
> sample(c("a","b","c","d","e"),100,replace=T)
> >>
> >> y <-
> sample(c("a","b","c","d","e"),100,replace=T)
> >>
> >> x.ordered <-
> >> factor(x,levels=c("e","b","a","d","c"),ordered=T)
> >>
> >> x.ordered
> >> y.ordered <-
> >> factor(y,levels=c("e","b","a","d","c"),ordered=T)
> >> y.ordered
> >>
> >> cor.test(x.ordered,y.ordered,method="spearman")
> >>
> >> require(pspearman)
> >>
> >> spearman.test(x.ordered,y.ordered)
> >>
> >> R commander has some menu options to deal with
> factors. R
> >> commander
> >> also provides a scripting window. Please do your
> students a
> >> favor, and
> >> show them how to use those commands.
> >>
> >>
> >> Cheers
> >> Joris
> >>
> >>
> >> On Thu, Jun 3, 2010 at 2:25 PM, Iasonas
> Lamprianou
> >> <lamprianou at yahoo.com>
> >> wrote:
> >>
> >> Dear colleagues,
> >>
> >>
> >>
> >> I teach statistics using SPSS. I want to use R
> instead. I
> >> hit on one
> >> problem and I need some quick advice. When I want
> to work
> >> with ordinal
> >> variables, in SPSS I can compute the median or
> create a
> >> barchart or
> >> compute a spearman correlation with no problems.
> In R, if I
> >> "read" the
> >> ordinal variable as numeric, then I cannot do a
> barplot
> >> because I miss
> >> the category names. If I read the variables as
> characters,
> >> then I cannot
> >> run a spearman. How can I read a variable as
> numeric, still
> >> have the
> >> chance to assign value labels, and be able to get
> table of
> >> frequencies
> >> etc? I want to be able to do all these things in
> R
> >> commander. My
> >> students will probable be scared away if I try
> anything
> >> else other than
> >> R commander (just writing commands will not make
> them
> >> happy).
> >>
> >>
> >>
> >>
> >> I hope I am not asking for too much. Hopefully
> there is a
> >> way
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >> ______________________________________________
> >>
> >> 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.
> >>
> >>
> >>
> >>
> >> --
> >> Joris Meys
> >> Statistical Consultant
> >>
> >> Ghent University
> >> Faculty of Bioscience Engineering
> >> Department of Applied mathematics, biometrics and
> process
> >> control
> >>
> >>
> >> Coupure Links 653
> >> B-9000 Gent
> >>
> >> tel : +32 9 264 59 87
> >> Joris.Meys at Ugent.be
> >>
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> >>
> >>
> >>
> >>
> >>
> >>     [[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.
> >>
> >>
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> 
> -- 
> Ghent University
> Faculty of Bioscience Engineering
> Department of Applied mathematics, biometrics and process
> control
> 
> tel : +32 9 264 59 87
> Joris.Meys at Ugent.be
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