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From | Steve Samuels <sjsamuels@gmail.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: AW: Non-reported s.e. for kappa |
Date | Wed, 14 Apr 2010 12:03:22 -0400 |
Martin- For Karen's set up (idj contains the subject rating for rater j), there is no official example that I can see. p615 shows counts of ratings, with each variable being a rating category. Also, for p615,, the command should be "kappa", not "kap", because the data are counts of assignments to three categories by five raters. This was terrible syntax decision: depending on the use of "kap" or "kappa" to distinguish between two data setups. One suggestion for a standard error: ************************************************* version 10.0 clear input case id2 id3 id6 id8 id9 id10 1 3 3 3 3 3 3 2 1 1 1 1 1 1 3 2 2 1 3 1 1 4 3 3 3 3 3 3 5 1 1 1 1 1 1 end kap id* jackknife r(kappa), mse: kap id* ci _jk_1 // First order unbiased estimates ************************************* n = 5 subjects doesn't seem like enough to draw many conclusions. It's interesting that the raters disagreed for only one subject. Steve Steve On Wed, Apr 14, 2010 at 10:52 AM, Martin Weiss <martin.weiss1@gmx.de> wrote: > > <> > > You do not need an imaginary dataset, as the official example does not > return the se, either: > > > ************* > webuse p615, clear > kap cat* > ret li > ************* > > The help file could make this fact clear, I think. BTW, a command reporting > a whole table inevitably runs into the problem which statistics it should > return. Just see what -summ- with a -varlist- hands back: The statistics for > the last variable in that -varlist-. The alternative would be to return a > -matrix-, of course... > > > HTH > Martin > > > -----Ursprüngliche Nachricht----- > Von: owner-statalist@hsphsun2.harvard.edu > [mailto:owner-statalist@hsphsun2.harvard.edu] Im Auftrag von Karen Wright > Gesendet: Mittwoch, 14. April 2010 16:38 > An: statalist@hsphsun2.harvard.edu > Betreff: st: Non-reported s.e. for kappa > > Dear All, > I have been working with kappa statistics and I have come across a > peculiarity that I don't fully understand. Searching the help files and the > statalist archive did not shed any light on the matter unfortunately. > After running a simple composite kappa on multiple readers (3 categories) I > then type -di r(se)- and obtain nothing! The results have not been cleared > from memory as typing -di r(kappa)- displays the kappa value. Does anyone > know why this is? > I am aware that test statistics cannot be calculated when the number of > ratings per subject vary. Is there something similar happening here?! > > I have shown below a snippet of the data and the commands used. Snippet of > data contains the diagnosis (=1,2, or 3) for 6 readers (id2-id10) on 5 > cases. [Done using Stata10 on Windows.] > > Thank you for taking the time to read this, > Karen > > ************************************************* > version 10.0 > > input case id2 id3 id6 id8 id9 id10 > 1 3 3 3 3 3 3 > 2 1 1 1 1 1 1 > 3 2 2 1 3 1 1 > 4 3 3 3 3 3 3 > 5 1 1 1 1 1 1 > end > > kap id* > di r(se) > di r(kappa) > > ************************************************* > > > > The Institute of Cancer Research: Royal Cancer Hospital, a charitable > Company Limited by Guarantee, Registered in England under Company No. 534147 > with its Registered Office at 123 Old Brompton Road, London SW7 3RP. > > This e-mail message is confidential and for use by the addressee only. If > the message is received by anyone other than the addressee, please return > the message to the sender by replying to it and then delete the message from > your computer and network. > > * > * 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/ > > > * > * 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/ > -- Steven Samuels sjsamuels@gmail.com 18 Cantine's Island Saugerties NY 12477 USA Voice: 845-246-0774 Fax: 206-202-4783 * * 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/