Background: Polygraph (lie-detector) tests are often routinely administered to government employees or prospective employees in sensitive positions. The article “How Not to Catch a Spy: Use a Lie...

Background:
Polygraph (lie-detector) tests are often routinely administered to government employees or prospective employees in sensitive positions. The article “How Not to Catch a Spy: Use a Lie

Detector” describes a National Research Council study in 2002, headed by

Questions:
What are the following probabilities?

1.
The probability that an employee is a spy and is “detected” to be one

2.
The probability that an employee is not a spy and is nevertheless “detected” to be one

3.
The overall probability that the polygraph “detects” an employee as being a spy