```Date: Tue, 6 Mar 2001 17:19:27 -0800 Reply-To: Dale McLerran Sender: "SAS(r) Discussion" From: Dale McLerran Subject: Re: square matrix for crosstabs Comments: To: smiller@wvmi.org Content-Type: text/plain Scott, It is not possible to force the square matrix with zero values for all cells in the missing row/column. However, what I have done in such circumstances is to add an observation which forces the matrix to be square. At the same time, I construct a variable (call it WEIGHT) with value 1 for every real observation, and value 1E-10 for every dummy observation. Now, if you run the proc freq using the WEIGHT statement to apply your constructed weight, you can compute KAPPA. By playing with the weight value for the dummy observations, you can see the sensitivity of KAPPA to the WEIGHT value. Even if you used dummy weights of 0.001, there would be little change to the value of KAPPA. At 1E-10, you have really added essentially nothing to the data, but tricked SAS into believing that there is a square matrix. Dale >Date: Tue, 6 Mar 2001 11:39:24 -0500 >Reply-To: "Miller, Scott" >From: "Miller, Scott" >Subject: square matrix for crosstabs >To: SAS-L@LISTSERV.UGA.EDU > >i have run into this delima before and decided to pose this question. when >trying to get kappa's for interrater analysis, many times one of the raters >will have no responses for one level of a variable, while the other rater >does. so when doing the table a*b a non-square matrix is produced and none >of the statistics are generated for the agree option. > >a/b 1 2 3 >----------------------------------- >1 5 10 15 >3 15 10 5 > > >is there a way to force a square matrix to be produced? in essence to >impose a format that includes all the levels for each variable? > > >a/b 1 2 3 >1 5 10 15 >2 0 0 0 >3 15 10 5 > > >thanks > >Scott D. Miller, MA > >Evaluation and Informatics Analyst >West Virginia Medical Institute >(304) 346-9864 ext 2240 > >Every good scientist should be one part P.T. Barnum and one part B.F. >Skinner. > >The goal of science is to build better mousetraps. The goal of nature is to >build better mice. > >Sumus quid sumus --------------------------------------- Dale McLerran Fred Hutchinson Cancer Research Center mailto: dmclerra@fhcrc.org Ph: (206) 667-2926 Fax: (206) 667-5977 --------------------------------------- ------------------------------------------------------------ --== Sent via Deja.com ==-- http://www.deja.com/ ```

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