Research approaches to the study of the accuracy of the detector differ in their degree of confidence in the truth. Field studies are real incidents; in studies by analogy artificial situations are considered. Both of these types of research, as if in a mirror, reflect the advantages and disadvantages of each other. In the first studies, the suspects are really worried about the outcome of the tests and thus show strong emotions. Another advantage of these studies is that they are experienced by the actual participants in the events, and not by the first-year students - the volunteers.
The weakness of field research lies in ignorance of truth, the knowledge of which is precisely the main advantage of research by analogy, in which the researcher himself appoints those who will lie and who will tell the truth. But the weakness of recent studies is that the "suspects" rates are low, and therefore the corresponding emotions are rarely shown. In addition, the subjects here are usually not at all like those who usually pass the polygraph test.

Field studies

Let us first consider why it is so difficult to establish the truth in these studies. Tests on a lie detector are usually conducted with people actually suspected of committing a crime, and are part of the investigation. And gradually it becomes known whether they confessed or not, are guilty or innocent, or the case will simply be closed. It would seem that having such information is easier to establish the truth, but it is not. Here is an excerpt from the conclusion of the BTO.
“Cases are usually not terminated due to the establishment of innocence, but rather due to insufficient evidence. And even if the jury justifies the defendant, it is still impossible to fully determine whether they are convinced of his innocence or they simply did not have enough evidence to find him guilty. There are many statements by defendants that are in fact confessions of less serious crimes; but, as Reskin notes, it is hardly possible to interpret such statements as an attempt to conceal a more serious crime for which the charge was brought. As a result, when using the detector’s testimony in the practice of criminal proceedings, a lot of mistakes arise (disbelief of truth) - in the case of conviction and (faith of lies) - in the case of dismissal of the case ” ^[144] .
And, despite the fact that it seems that these problems are resolvable by simply convening a commission consisting of qualified specialists and making an informed decision about guilt or innocence, in fact there are two fundamental difficulties. Experts do not always come to an agreement, and even if this happens, they still do not, as a rule, have complete confidence in their own right. Even the “open-hearted” confession of the accused does not always remove the problem; sometimes completely innocent people are recognized. Actual, fully confirmed confessions are so small that on their basis no serious conclusions can be made. And almost all field studies suffer from the fact that usually no evaluation is made of the typicality of the cases selected for the study.

Studies by analogy

The situation is no better with studies by analogy, but there the problem lies elsewhere. There, there is complete confidence in the truth, for the researcher himself designates who is to be a “criminal” and who is not guilty. However, can a conditional crime as excite a person as a real crime? Researchers who make such experiments try to interest the participants in any reward if they are not caught by the detector. Sometimes the opposite happens: the subject is threatened with punishment in case of discovery of lies, but the ethical foundations of such punishments are extremely unworthy, and besides, the subject begins to doubt the real value of the experiment conducted in this way. Practically everyone using the test questions technique resorts to research by analogy to the conditional crime variant described by Reskin.
“Half of the subjects receive a notification that, in connection with the theft of the ring that occurred in the next office, they are invited to undergo a detector test in order to make sure that they did not participate in this theft. In addition, they are told that if their testimony is found to be true by the lie detector, they will receive a material reward. At the same time, the other half talk about how and what crime they allegedly committed ... (They lured the secretary out of the office, went there in her absence, searched the table, found the ring and left.) They are asked not to disclose the fact of participation in the experiment and have alibi ready. They are also asked not to disclose the details of the crime to the detector operator, because if he finds out about their guilt, they will not receive the promised remuneration ($ 10) ” ^[145] .
People try to pretend to be real criminals, and therefore inevitably the question arises of the emotions arising from such deception. Since the detector notes emotional arousal, committing a conditional crime will help to assess the accuracy of the detector only when the same emotions are raging in a person as when committing a crime of the present. Chapter 2, “Why a lie sometimes fails,” says that at the moment of uttering a lie, a person may have three emotions, and for each of them I explained about their intensity. Let us consider whether the emotions caused by a conditional crime committed for the purpose of checking the accuracy of a lie detector are similar to the emotions arising from a real crime.
Fear of exposure. Stronger than all determines the degree of fear of disclosing fraud that is currently at stake. In chapter 2 "Why lies sometimes fails," I suggested that the greater the reward for success and the more serious the punishment for failure, the stronger the fear of being exposed. And from this pair of circumstances, perhaps the seriousness of the punishment is more thorough. It will also influence a person who speaks the truth because of fear, as if his words are not interpreted incorrectly, and on the one who lies, because of the fear of exposure. Both will suffer because of the same feeling. But when committing a conditional crime, the reward is low, and the punishment, as a rule, is completely absent - therefore, neither a liar nor a truth telling person are afraid of exposure. Probably, the participants in the tests are worried about receiving a reward, but this emotion is practically nothing compared to the fear of both the lie and the innocent when investigating real crimes.
Remorse. Guilt is certainly strengthened when much is at stake, but when a conditional crime is committed, it is reduced by the fact that the lie is allowed, demanded and even necessary for carrying out specific work. In addition, participants are usually told that they must lie for the sake of science. As a result, the experiment participants do not feel guilty for their deception.
Delight of cheating. The excitement of a call, of being able to outwit someone, is a liar who feels particularly strong if he has a reputation as an unsurpassed deceiver. Inflating a detector is undoubtedly very tempting, and this emotion is usually very strong, if, of course, there are no others — fear and / or guilt — that can spray it ^[146] .
In addition, the enthusiastic delight is usually and generally not true to the truthful person.
From the above analysis it can be seen that conditional crimes can adequately produce only one of the three emotions expected in the investigation of a real crime - the delight of cheating. Moreover, as a rule, only liars experience this emotion. Thus, since in the case of a study by analogy, only a liar will experience strong emotional arousal, the exposure will be very easy; in any case, it is much easier than when investigating real crimes, when a person who speaks the truth is more inclined to experience the same emotions as a liar. Therefore, the use of conventional crimes contributes to the overestimation of the accuracy of the detector.