I mentioned this in class on Thursday (Oct 21), the US census carried out a supplemental survey on Internet use in 2011. You can read about the cognitive pre-testing they did (using a “think-aloud procedure with verbal probing”) here. This process is much like the qualitative interviewing techniques you are learning in class, but in this context it is to check the comprehensibility of survey questions toward the end goal of designing questions that can be comprehended accurately without further discussion or probing.