I have a check box grid question with industry sectors along the top and frequencies of visiting them down the side (ie they are the row headers). It only makes sense to have respondents select one frequency of visit per sector. I have found (under Validation) how to require a minimum of one row header response per column, but not how to create a maximum (ie I want a minimum of one and a maximum of one, response per column).
I have the Collaborator package.
Can anyone help please?