Good job classifying your variables here. As far as the last question, keep in mind that generalizability is generally an all-or-nothing issue. Either the survey is conducted in such a way as to produce a sample that is large enough and diverse enough to represent the population, or it is not. Given that you'd be surveying one particular Girl Scout Cookie stand in one part of one town in the entire country, do you think it would be possible to obtain a representative sample