In all honesty Stephen,
if you manage to open my eyes to R, I'll always be
greateful. I had a go, but failed. Any worked examples for
me, with the commands, and a data file with 5 lines of data
to see how they look like? I'll be forever greateful.
Honestly
Jason
----- Original Message Follows -----
From: Stephen Z Levine <[log in to unmask]>
To: [log in to unmask]
Subject: Re: Parscale
Date: Wed, 17 Jan 2007 17:31:33 +0200
> Hi
> Why not use the ltm
> package of R?
> www.r-project.org
> S.
>
> ----- Original Message -----
> From: "Iasonas Lamprianou" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Wednesday, January 17, 2007 8:22 AM
> Subject: Re: Parscale
>
>
> > Thanks,
> > do you happen to know his email address?
> > Jason
> >
> > ----- Original Message Follows -----
> > From: "A. Beaujean" <[log in to unmask]>
> > To: [log in to unmask]
> > Subject: Re: Parscale
> > Date: Tue, 16 Jan 2007 14:11:52 -0600
> >> You can contact Leo Stamm (Sp?) at SSI about the issue.
> He >> does a good job at getting back with you, but as far
> as I >> can tell, it is just part of the problem with the
> SSI IRT >> suite. That is, it requires a lot of monkeying
> around to >> get convergence on some data sets.
> >>
> >> On 1/16/07, Iasonas Lamprianou
> <[log in to unmask]> >> wrote: >
> >> > Thanks for sharing your experience Alex,
> >> > but does anyone have a solution? Or I think this is a
> >> > problem of all IRT software? Anyway, how much can you
> >> > trust a software with such a peculiar behaviour?
> >> >
> >> > Jason
> >> >
> >> > ----- Original Message Follows -----
> >> > From: "A. Beaujean" <[log in to unmask]>
> >> > To: [log in to unmask]
> >> > Subject: Re: Parscale
> >> > Date: Tue, 16 Jan 2007 13:30:38 -0600
> >> > > I have a similar thing happen in BILOG-MG when I
> have >> > > a large data set. When I put priors in the
> parameters, >> > > it sometimes works; likewise, changing
> the number of >> > > quadrature points.
> >> > >
> >> > > Alex
> >> > >
> >> > >
> >> > > On 1/16/07, Iasonas Lamprianou
> >> > > <[log in to unmask]> wrote: >
> >> > > > Dear friends,
> >> > > > I have been working with Parscale for some time,
> and >> > > > I was always anxious when the Newton Cycles
> (after >> > > > the E-M Cycles converge) did not converge
> (actually >> > > > usually diverge). This time, its the
> same story. The >> > > > Newton Cycles diverge. When I
> fiddle with the >> > > > settings, Parscale manages 2-3
> cycles and then >> > > > diverges again. Anyone knowing
> any tricks to make >> > > this creature converge? >
> >> > > > Jason
> >> > > >
> >> > > > ----- Original Message Follows -----
> >> > > > From: Paul Barrett <[log in to unmask]>
> >> > > > To: [log in to unmask]
> >> > > > Subject: Very important paper on SEM modeling
> >> > > > Date: Fri, 5 Jan 2007 13:50:22 +1300
> >> > > > > Hello again
> >> > > > >
> >> > > > > Almost forgot - but I think this is a very
> >> > > > > important and readable paper for anyone
> >> > > > > contemplating using hierarchical factor models
> in >> > > > > SEM ... It's clearly written, and that
> nested >> > > > > (bifactor) model is a very nice way of
> modeling a >> > > > general factor. I've used this myself
> recently ... > >> > > > > Gignac, G. (2007) Multi-factor
> modeling in >> > > > > individual differences research:
> Some >> > > > > recommendations and suggestions.
> Personality and >> > > > > Individual Differences, 42, 1 ,
> 37-48. >> > > > >
> >> > > > > Abstract
> >> > > > > This paper offers some commentary and
> >> > > > > recommendations relevant the multi-factor
> modeling >> > > > > in individual differences research.
> Several >> > > > > similarities and distinctions between
> oblique >> > > > > factor modeling, higherorder modeling,
> >> > > > > Schmid-Leiman transformations, and nested
> factors >> > > > > modeling are discussed. An empirical
> illustration >> > > > > of the various multi-factor models
> is presented, >> > > > > based on 18 items derived from
> three Neuroticism >> > > > > facets within the NEO PI-R.
> Researchers are >> > > > > encouraged to always perform a
> Schmid-Leiman >> > > > > transformation to a higher-order
> model solution, >> > > > > as well as to consider the
> possibility that a >> > > > > nested factors model will
> yield superior model fit >> > > > , in comparison to a
> higher-order model, as well as >> > > > less ambiguous
> factor solutions. > > >> > > > > Another recent paper on
> the same topic - but >> > > > > focused more in the
> Quality of Life literature is: >> > > > >
> >> > > > > Chen, F.F., West, S.G., and Sousa, K.H. (2006)
> A >> > > > > comparison of bifactor and second order
> models of >> > > > > quality of life. Multivariate
> Behavioral Research, >> > > > 41, 2, 189-225. >
> >> > > > > Abstract
> >> > > > > Bifactor and second-order factor models are two
> >> > > > > alternative approaches for representing general
> >> > > > > constructs comprised of several highly related
> >> > > > > domains. Bifactor and second-order models were
> >> > > > > compared using a quality of life data set (N =
> >> > > > > 403). The bifactor model identified three,
> rather >> > > > > than the hypothesized four, domain
> specific >> > > > > factors beyond the general factor. The
> bifactor >> > > > > model fit the data significantly
> better than the >> > > > > second-order model. The
> bifactor model allowed for >> > > > > easier
> interpretation of the relationship between >> > > > > the
> domain specific factors and external variables >> > > ,
> over and above the general factor. Contrary to the >> > >
> > > literature, sufficient power existed to >> > > > >
> distinguish between bifactor and corresponding >> > > > >
> second-order models in one actual and one >> > > > >
> simulated example, given reasonable sample sizes. >> > > >
> Advantages of bifactor models over second-order >> > > >
> models are discussed. > > >> > > > > Regards .. Paul
> >> > > > >
> >> > > >
> ___________________________________________________ >> > >
> > > > Paul Barrett >> > > > > Mob: +64-021-415625
> www.pbmetrix.com >> > > > > <http://www.pbarrett.net/>
> Skype: pbar088 >> > > > > [log in to unmask]
> >> > > > >
> >> > > > >
> >> > > >
> >> > >
> >> > >
> >> > >
> >> > > --
> >> > > ***************
> >> > > A. Alexander Beaujean, Ph.D.
> >> > > http://myprofile.cos.com/abeaujean
> >> > >
> http://www.baylor.edu/soe/faculty/index.php?id=38476 >> >
> > >> > >
> >> > >
> >> > > "General impressions are never to be trusted.
> >> > > Unfortunately when they are of long standing they
> >> > > become fixed rules of life, and assume a
> prescriptive >> > > right not to be questioned.
> Consequently those who are >> > > not accustomed to
> original inquiry entertain a hatred >> > > and a horror of
> statistics. They cannot endure the >> > > idea of
> submitting their sacred impressions to >> > >
> cold-blooded verification. But it is the triumph of >> > >
> scientific men to rise superior to such superstitions, >>
> > > to devise tests by which the value of beliefs may be
> >> > > ascertained, and to feel sufficiently masters of >>
> > > themselves to discard contemptuously whatever may be
> >> > > found untrue." --Sir Francis Galton, FRS >> > >
> >> >
> >>
> >>
> >>
> >> --
> >> ***************
> >> A. Alexander Beaujean, Ph.D.
> >> http://myprofile.cos.com/abeaujean
> >> http://www.baylor.edu/soe/faculty/index.php?id=38476
> >>
> >>
> >>
> >> "General impressions are never to be trusted.
> >> Unfortunately when they are of long standing they
> become >> fixed rules of life, and assume a prescriptive
> right not >> to be questioned. Consequently those who are
> not >> accustomed to original inquiry entertain a hatred
> and a >> horror of statistics. They cannot endure the idea
> of >> submitting their sacred impressions to cold-blooded
> >> verification. But it is the triumph of scientific men
> to >> rise superior to such superstitions, to devise tests
> by >> which the value of beliefs may be ascertained, and
> to feel >> sufficiently masters of themselves to discard
> >> contemptuously whatever may be found untrue." --Sir
> >> Francis Galton, FRS
> >>
> >
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