Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down on April 23, and its replacement, is already up and running.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

st: RE: reliability with ordinal data-Kendall's w?

From   Nick Cox <>
To   "''" <>
Subject   st: RE: reliability with ordinal data-Kendall's w?
Date   Mon, 13 Dec 2010 20:12:47 +0000

It seems to me that Somers' [NB] d is very well supported in Stata given Roger Newson's routines. 

I can't see much point to plots of the form re-invented by Bland and Altman in this case. Nor does the limits of agreement approach transfer other than queasily to a 4-point graded scale. -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:

© Copyright 1996–2015 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   Site index