Newer methods such as the CIT claim to be more accurate than the polygraph at detecting lies and knowledge of information that only a guilty party would know.

What kinds of experimental methods could be used to validate the CIT?

The Concealed Information Test or CIT, also known as the Guilty Knowledge Test or GKT, is known to be pretty useful when interrogations are to be had. However, if there is a need to be more accurate there are some ways to validate the CIT. For example, one could create a set of background questions as well as about the crime for both guilty and innocent people. Then, some people would complete the task others not, and then ask other to lie and since it is already known if they are lying or not it could also reflect how accurate the test is after comparing results.