Date:         Mon, 20 Nov 2006 23:47:46 -0500
Reply-To:     Ming Chen <chenming@GMAIL.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Ming Chen <chenming@GMAIL.COM>
Subject:      Should the binary, categorical variables be standardized?
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Hi All,

Now I am reading the famous "The Elements of Statistical Leaning" and trying
to carry out the some examples using SAS.
For one example in the linear regression section, the authors claimed that
they fitted the linear model after standardizing all the predictors.
However, among the predictors, there are two categorical variables.
Basically I have two questions:

1. I can understand that why standardize continuous variables. But how about
the categorical variables?
2. Suppose we can,  does the standardization mean we can transform the
categorical variables into continuous variables?

Also, it would be great you can give me some references about how and when
to rescale the variables.

Thanks

Ming