Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
st: RE: RE: reliability with ordinal data-Kendall's w?
From
Nick Cox <[email protected]>
To
"'[email protected]'" <[email protected]>
Subject
st: RE: RE: reliability with ordinal data-Kendall's w?
Date
Tue, 14 Dec 2010 11:55:42 +0000
On the graphics,
. webuse rate2
(Altman p. 403)
. tabplot rad?, percent showval
gives an example of -tabplot- (SSC) with such data.
Nick
[email protected]
Nick Cox
[...] -tabplot- from SSC offers one of various graphical alternatives. Diagonal agreement and off-diagonal disagreement will be pretty clear.
Ploutz-Snyder, Robert (JSC-SK)[USRA]
I need to perform a reliability analysis among two raters who rated the same observations independently. Observations are rated on an ordinal scale, taking 4 distinct values in increasing order. Neither rater is assumed the "gold standard." There are a LOT of ties in my dataset (a good thing in terms of rater reliability).
I came across some web hits about Kendall's W, which is different from the more familiar tau. Can anyone attest to whether this is the best way to go about a reliability analysis with ordinal data? Is there a way to implement on Stata?? How does W differ from tau, and Somer's d??
Are there other/better methods that I should be considering too?
Also--for those knowledgeable about reliability analyses... I think that eventually I would like to graph these data with something akin to the Bland-Altman plots. Do you take issue with that approach given that the data are not continuous? Are the BA Limits of Agreement valid in this situation??
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/