In my dataset the data is usually coded 1 for case and 2 for the reference. I consulted a book that mentioned I did not have to change this values to 0 and 1, because SPSS would automatically understand 1 as 2 and 2 as 0. Is that true? But in the case a variable has more than two categories, and I define categorical variables and use the indicator contrast to set the reference category, SPSS will set the reference to 0. Would that be a problem if all other values are 1 and 2, 1 being the reference variable?
Also, my dataset has a variable like with the following classes
0 - white
2 - Hispanic
9 - unknown
Question: Should I change this so the categories start as 1-white, 2- black, 3- hispanic,