A survey like this would have more meaning if they also took into account the educational level of the respondent. There were a number of questions in the survey that seemed to be between choices that were either syntactically bad, but colloquially correct english, or syntactically correct, but less common colloquially. Overall, the data collected on the survey takers seemed a little sparse.

Linguists use these maps for several purposes. Ones, such as these seem to be, that ask where you live - rather than where you are from - are often used to help in discerning migratory patterns. Look at all the transplanted yankees in Florida who don't say "ain't".

These maps seem rather random. It appears that they don't ask the key question of where somebody is from, as opposed to where they live now. Key item is trying to determine the distribution. Or did I miss that part?

warsh, 'front room', 'Hey' for 'Hi' and 'sodey' for soda all peg you as central Illinois.

I don't think this is meant to be comprehensive. There are
probable plenty of other things that could be mapped: how do
you say "drawer"? My wife also looks at me funny for that
one. I like how they don't just consider soda v. pop but
include other subtle ones like tonic.

People sometimes say I have no accent, but from these I can
clearly pick out where in the US I come from.

All that and they forgot "wash", pronounced as "warsh" in some places.