Re: st: RE: combining reliability trial data

[Nick Cox <njcoxstata@gmail.com>]

The larger question is "to combine the data somehow to make use of it
all" and the answer would be a model that matches your idea of the
data generation process.

Nick

On Mon, Feb 13, 2012 at 5:13 PM, Nick Cox <n.j.cox@durham.ac.uk> wrote:
> The error in using -bagroup- arises, I guess, because it lacks a -version- statement. Inserting a line such as
>
> version 7
>
> after each -program- statement is likely to fix the problem that braces are used within the program in ways that clash with present rules. I have not tested this guess and there may be other problems.
>
> See also [P] version for details here.
>
> -bagroup- comes from the following place. Please remember that you are asked to explain _where_ user-written programs you refer to come from.
>
> STB-55  sbe33 . . . . Comparing several methods of measuring the same quantity
>        (help baplot, bagroup, bamat, sdpair if installed)  . . . . .  P. Seed
>        5/00    pp.2--9; STB Reprints Vol 10, pp.73--82
>        commands implementing the Bland-Altman approach to comparing
>        two or more measurement methods;  also alternative command to
>        sdtest based on Pitman's method giving confidence intervals
>        for variance ratios of paired data
>
> Nick
> n.j.cox@durham.ac.uk
>
> Hilary Taylor
>
> I am hoping to test the inter- and intra-rater variance of a measurement
> method.  I had two raters (R1 and R2) perform measurements on 28 items and
> each rater measured the set twice (t1 and t2).  The measurements are scale.
>
> I have drawn up some Bland & Altman plots and have performed Pitman's
> tests.  I have carried this out for inter-rater (R1t1 vs R2t1) and
> intra-rater (R1t1 vs R1t2), however I would really like to combine the data
> somehow to make use of it all.  I thought the command 'bagroup' (Paul Seed,
> 2000) might be useful but have been unable to explore this because the
> following error comes up:
>
> bagroup  t1_r1  t2_r1  t1_r2  t2_r2
> program error:  matching close brace not found
>
> I would be grateful if you could tell me firstly, if this would be a useful
> thing to do (if I can get it working) and secondly, if you have any
> suggestions for a better way for me to combine these data (I would like to
> create plots and associated stats)?
>
> (I am using Stata/SE 11.2)

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