So in response to your #2 -- I don't get it. We already know that stuttering severity is influenced by "social anxiety" -- are you looking for subgroups of people who stutter that are more and less sensitive to "social anxiety"? If so, again you have more than one variable -- the effect of alcohol and temperament (c.f., personality). and just a technical note on #6 -- speech and language are not the same thing. If you're looking at stuttering (moments of stuttering, I presume) you're actually looking at speech production, not language. There are other problems, but I'll leave that for you to discuss with you advisor. I'm sorry I'm just not getting the purpose of your proposal ... and not to be a dick, but if you're recruiting subjects you need to have approval from your institutional review board (if you're in the US, at least) source: I'm a PhD candidate in the area of stuttering.