Edited by author 03-07-2004 01:53 PM
Anjum :

/m3,question 2: I think for those variable, 0 means missing. The class index starts at 1.

My question is if we should treate symbolic variables as regular regression variables, such as ZIP, GENDER, FEDGOV.

My guess is that usually we use binary data as an indicator to combine with other variables. For example, assume we have variables x_i taking real value and x_j taking binary valu. Then there might be a term in the regression with form \beta * <x_i,x_j>. <,> means inner product.

Just my two cents.