"Recognition Test “Polygraph techniques can be divided into two major categories, knowledge-based tests, also called recognition tests, and deception based tests. Ther ecognition test family of PDD techniques includes; peak of tension tests (known & searching/probing), acquaintance (stimulation) tests and concealed information (Guilty Knowledge Test) tests. They attempt to determine if the examinee has knowledge only available to persons directly involved in an incident of concern.” [1]"(...)