posted 11-07-2010 09:04 AM         

---

My son is facing expulsion from school based an accusation from another student. The other student along with another witness says he sold them a drug. He tells us he did not do this and wants to take a polygraph test to prove he is telling the truth? The school believes the other kid and I do not know any other way to prove his innocence. I think he is telling the truth although he has lied to use in the pass. What Should we do?

IP: Logged

posted 11-10-2010 09:04 AM            

---

What you do is up to you. If he is a suitable candidate for polygraph, then it is an option you should consider - providing the results will be considered by the decision makers. Would the other party also agree to a test? If so, "pairing" the results (as long as they are consistent) would make for a much stronger case. For example, assume polygraph is 90% accurate. Thus, you'd have a 10% chance of error. If your son were to pass and the other were to fail (or the opposite were to occur), then the chance of both being wrong is 10% of 10%, or 1%.

(The NAS found a median accuracy of 86 or 87%, and scientists at the University of Utah found it to be as high as 96.5% accurate, so no matter what figures you use, you're talking a very small chance of error if you can work that out.)

IP: Logged