st: Mixed logit - rand(varlist) option

[SAM MCCAW <sam2stata@gmail.com>]

Hello,

In the mix logit commands one must specify variables with random
coefficients: i.e.

 rand(varlist) is required and specifies the independent variables
whose coefficients are random. The random
        coefficients can be specified to be normally or lognormally
distributed (see the ln() option).  The variables
        immediately following the dependent variable in the syntax are
specified to have fixed coefficients (see the
        examples below).

I am little confused about how to identify " independent variables
whose coefficients are random"

Thanks for your help.

SAM
*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/faqs/resources/statalist-faq/
*   http://www.ats.ucla.edu/stat/stata/