Polygrams [i.e., polygraph charts] are polygrams. They measure and record physiological reactions. And they do so very well, but one cannot look at a polygram and say, "That is a lie." It may be a reaction, but no one can say that it is a lie. An examiner may interpret a reaction to be a lie, but in actual practice, the examiner also is observing the subject, listening to verbal explanations, and making a judgment about the person's truthfulness. Some examiners are simply better than others.

Because of their experience in talking with people and their success in obtaining confessions, polygraph examiners may come to feel very confidant [sic] about making a determination of truth or deception based on their charts. Indeed, if a person is reacting, it is the examiner's job to determine why and to obtain a confession if they believe that deception is the cause of the reactions. But without a confession, polygrams are still just polygrams.

The first general category I call the "positive statement of deception." In this approach, the interrogator immediately places the subject on the defensive by telling the subject that the instrument shows positively that the subject is not answering the questions truthfully, and the interrogator then demands explanations. [Remember Harrelson's statement that without a confession, polygrams are just polygrams: the instrument cannot show positively that you are not answering truthfully] This approach leaves no "out" for the subject except for his or her admission. The subject has now to admit not only the issue in question, but also the lie, and for that reason, this approach might not be successful. Surprising though it may seem, I have found this type of approach to be most effective in rape or homicide cases, even though the subject knew that the offense carried the death penalty.

The second general category I call the "passive statement of deception." Here, the interrogator tells the subject that the instrument shows positively that he "remembered something else" [which is a lie: as Harrelson himself concedes, "polygrams are polygrams"] during the test following his answer to questions, and requests an explanation of what he remembered. Notice that in this approach the interrogator gives the subject an "out" for explaining the lie and also for changing his or her story regarding the crucial issue. This approach has been successfully used in cases involving thefts, especially when a previous admission has been obtained.

A third general category involves the "analogy" approach. The interrogator does not refer to the test or the subject's reactions specifically. He infers deception by citing various hypothetical situations designed to establish for the subject a psychological climate which plays down the moral and/or legal wrong in commission of the crime, underscores human imperfections and the tendency to make mistakes, and emphasizes the stigma attached to a person who lies about a matter, especially where the truth is already known. For instance, he may assure the subject that everybody makes mistakes and the interrogator has made many as well. The interrogator may further assure the subject that many people have done this very same thing, and when all the truth was known, were found to have had a very good reason for so doing. The interrogator could go on and explain how senseless it is to attempt to lie to someone about a matter when that person knows he is lying. This could create empathy which could be advantageous for the examiner, who can then request that the subject tell the entire truth in the matter.

A fourth general category is similar to the second category mentioned previously. This is the "suggestive" approach in which the examiner tells the subject that the instrument shows a "disturbance" on a question and asks him to tell "what he thought of there." [Note: this approach is very common in polygraph screening examinations.] He doesn't positively say that the subject was lying, but he suggests that the subject has an explanation, thus giving the subject an "out" for changing or enlarging his or her story. [Note: explaining what you were thinking of when you answered a question is not a good idea; don't let your polygrapher turn the polygraph chamber into a confessional. See Chapters 3 & 4 of The Lie Behind the Lie Detector. Remember, as Harrelson admits, one cannot look at a polygram and state "that is a lie."]

The fifth general category of approach I call the "bypass" or "leap frog" approach. The interrogator positively infers that the question of commission has been definitely established by the instrument, and is no longer a subject of interest or debate. The interrogation is directed strictly at motivation and the pressures which "forced" the subject to act as he or she did. The subject is not even permitted to talk about the commission; he firmly rejects any such attempt by telling the subject that he isn't interested in that phase anymore, because the instrument supplied the answer. [It didn't: as Harrelson concedes, "without a confession, polygrams are still just polygrams."]

The sixth general category encompasses the "unexpected" or the "shock" approach. Here, especially, the imagination and the role-playing ability of the examiner is given free rein. This approach would include such tactics as suddenly shutting off the instrument in the middle of a test, removing the attachments from the subject and requesting that he get down on his knees to join you in praying for his soul and courage to tell the truth. This approach, if used with sincerity and conviction, can carry a tremendous psychological impact on certain subject types. There are other techniques which fall in the same general category, but I believe this one sufficiently illustrates the matter. I'd like to add that I do not advocate any form of hypocrisy or sacrilegiousness by this technique. The interrogator must be sincere in his conviction that the subject should tell the truth, or he's treading on dangerous ground, morally.