darkcobra2005 wrote on May 27^th, 2005 at 5:26pm:

Regarding abilities to detect countermeasures:   We are not perfect in this area, however we have been detecting numerous counter measures and the subjects tested have admitted to this.  They, in many cases have recieved information from antipolygraph.org.  This is disturbing to me because most of the subjects are otherwise good candidates.  The use of counter measures does disqualify them from further consideration which is unfortunate.

I'd just like to add that, in my own experience, this sort of thing appears to be raw guesswork on the part of polygraph examiners (unless, of course, someone does something obvious like observably tensing, noisily modifying one's breath, etc.).  My evidence for this was my three polygraph examinations with NSA (which presumably hires competent examiners and has access to any and all research on countermeasure detection).  My use of countermeasures went entirely undetected through all three examinations, even though the first polygrapher noted what nice charts I was producing.  The second said nothing at all about it.

And to answer the inevitable questions: I didn't lie about countermeasure use (or about anything else, for that matter).  I was never accused of using them.  Prior to my third examination, the polygrapher noted that it's common for people, after coming back for multiple polygraph exams, to do some research, and asked me whether I had.  I chose to answer this question truthfully, and told him I was familiar with countermeasures.  He told me that if I used countermeasures, he'd kick me right out the door!  

It's worth noting that he didn't kick me out.