https://communities.sas.com/t5/SAS-Procedures/qualitative-variables-in-reg-model/m-p/35518#M8771 When you generate your own recoding, as described, you only need to include two of the variables as the three categories represent two degrees of freedom. Wed, 16 Jun 2010 13:02:26 GMT Doc_Duke 2010-06-16T13:02:26Z https://communities.sas.com/t5/SAS-Procedures/qualitative-variables-in-reg-model/m-p/35516#M8769 I want introduce in a proc reg a qualitative variable. My variable is genotype VKORC1 in 3 cathegories N/N, N/m, m/m. How can i recode this variable to introduce it in my regression model? Tue, 15 Jun 2010 08:47:33 GMT https://communities.sas.com/t5/SAS-Procedures/qualitative-variables-in-reg-model/m-p/35516#M8769 deleted_user 2010-06-15T08:47:33Z https://communities.sas.com/t5/SAS-Procedures/qualitative-variables-in-reg-model/m-p/35517#M8770 Looks like:<BR /> <BR /> <BR /> N/N N/m m/m<BR /> 1 0 1<BR /> 0 1 1<BR /> 0 0 1<BR /> <BR /> <BR /> <BR /> <BR /> Ksharp Wed, 16 Jun 2010 07:04:08 GMT https://communities.sas.com/t5/SAS-Procedures/qualitative-variables-in-reg-model/m-p/35517#M8770 Ksharp 2010-06-16T07:04:08Z https://communities.sas.com/t5/SAS-Procedures/qualitative-variables-in-reg-model/m-p/35518#M8771 When you generate your own recoding, as described, you only need to include two of the variables as the three categories represent two degrees of freedom. Wed, 16 Jun 2010 13:02:26 GMT https://communities.sas.com/t5/SAS-Procedures/qualitative-variables-in-reg-model/m-p/35518#M8771 Doc_Duke 2010-06-16T13:02:26Z