The chi-square does not need your two categorical variables to have equal levels, nor limitation for the number of levels.
The Chi-square procedure is as follow: χ^2=∑_(All Cells)▒〖(Observed-Expected)〗^2/Expected Expected Cell= E_ij=n((i^th RowTotal)/n)((j^th RowTotal)/n) Degree of Freedom=df= (row-1)(Col-1) This way should not give you any errors if your calculations are all correct. I usually use SAS for calculations like this. Below is a sample code I wrote to test whether US_State and Blood type are independent. You can modify it for your data and should give you no error. data bloodtype; input bloodtype$ state$ count@@; datalines; A FL 122 B FL 117 AB FL 19 O FL 244 A IA 1781 B IA 351 AB IA 289 O IA 3301 A MO 353 B MO 269 AB MO 60 O MO 713 ; proc freq data=bloodtype; tables bloodtype*state / cellchi2 chisq expected norow nocol nopercent; weight count; quit; Best Ramin ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
