[Rasch] Rasch to G-theory
liasonas at cytanet.com.cy
Fri Apr 20 03:29:58 EST 2012
Than you very much Mike
----- Original Message Follows -----
From: Mike Linacre <rmt at rasch.org>
To: <rasch at acer.edu.au>
Subject: Re: [Rasch] Rasch to G-theory
Date: Tue, 10 Apr 2012 19:43:51 +1300
> The variances needed to compute a Rasch-based equivalent to a
> Generalizability Coefficient (G) are in Facets Tables 5 and 7.
> My apologies that the "explained variance" computations at
> www.winsteps.com/facetman/table5.htm do not show the last step in the
> computation. It is:
> G = (Explained variance% by target facet) / 100
> Please verify this value of G makes sense for your data. A more specific
> Generalizability Coefficient may be more meaningful to your audience.
> Variance terms similar to
> page 20 can be extracted from Facets output. These can be used to compute a
> more focused Generalizability Coefficient.
> Mike L.
> At 4/10/2012, you wrote:
> >can anyone direct me to a paper which explains how to use Rasch measured
> >reported by Facets to compare the results with G-theory estimates? For
> >example, I can read in the Facets output the sd of item measures, the sd
> >of rater measures and the sd of person measures. How can I produce an
> >index which is similar to the variance attributed to markers as computed
> >in generalizability theory? Or maybe this is not possible? A good search
> >on the internet did not help me a lot, although I reached a paper by
> >Macmillan (2000) which, unfortunately, I cannot have access.
> Mike Linacre
> Editor, Rasch Measurement Transactions
> rmt at rasch.org www.rasch.org/rmt/ Latest RMT: 25:4 Spring 2012
> Rasch mailing list
> Rasch at acer.edu.au
> Unsubscribe: https://mailinglist.acer.edu.au/mailman/options/rasch/liasonas%40cytanet.com.cy
More information about the Rasch