Audience Identification (Secondary Sources)

For My Seconday data I have decided to use Burton's theory on audience identification. However, when using his theory I have to be carful how I use him idea' s in my questionnaire. For example, I cannot ask my audience for the questionnaire what social class they are? as they may get offended. Also, I have to make sure my questions are not biased for my social desirability as this would not make my questionnaire fair and will not be getting honest answers.