Non model question in a model form

I am working on a Rails app where people sign up and have a profile. When they are first signing up, they fill in their profile but I have an additional question when they are creating their account that alters the initial configuration of the account but is never used afterwards, so I don’t want to include it in the profile. It is a multiple choice question with certain validation rules. How do I go about including this in the form?

I am working on a Rails app where people sign up and have a profile. When they are first signing up, they fill in their profile but I have an additional question when they are creating their account that alters the initial configuration of the account but is never used afterwards, so I don't want to include it in the profile. It is a multiple choice question with certain validation rules. How do I go about including this in the form?

How serious do these validations need to be? You may be able to do all of this in the view, using JavaScript for validation. As long as the result of the choice being made here is backed up by actual validations on your model, you should be fine.

Walter