Polygraphy is serious science. In all instances of polygraph exams, the outcome of the lie detector test can have serious consequences for the examinee. Whether the test is for pre-employment or employee screening, sex offender or victim testing, or criminal investigations – polygraph exam results can change the examinee’s life forever.
So, it’s vital that the polygraph exam procedure and the examiner adhere to the highest forensic standards and best practices. Whether the test is for criminal or civil case requirements in the public or private sector, polygraph examiners must ensure they operate the lie detector test to certified standards set by the American Polygraph Association (APA).
Polygraph Examiners – Understanding Standards of Practice
The APA regulates polygraph examiners in the United States. The organization’s goal is to promote the highest degree of examiner decision accuracy in all credibility assessments.
To achieve this, the APA sets the forensic standards of best practices that all examiners must follow when preparing for and conducting a polygraph exam and in an exam post-analysis.
All polygraph examinations must be conducted in compliance with the governing local, state, and Federal legislation and regulations surrounding the preparation, execution, and analysis of these tests.
Let’s unpack the forensic standards of practice.
The Basic Polygraph Definitions
Polygraph Examinations
A polygraph exam, also known as a “lie detector,” is a “psychophysiological” test to indicate “deception” in an examinee by the examiner. This evidence-based, standardized exam tests the confidence level or margin of uncertainty surrounding the conclusion of deception (lying) or possession of knowledge/ information regarding a specific test issue.
The test data in the polygraph exam involve a combination of physiological functions shown to vary widely when the examinee experiences different stimuli in the test environment under examiner questioning.
These stimuli play the function of indicating deception or truth-telling in the examinee in response to the examiner questioning the examinee with relevant investigation target stimuli. The psychological basis of the examinee’s reactions to the polygraph stimuli involves a combination of cognition, attention, behavioral, and emotional conditions.
The polygraph exam consists of an interview phase where the examiner preps the examinee for the test, clarifying the reasons for the polygraph exam. The data acquisition phase involves recording the examinee’s physiological responses to the test questions producing the physiological stimuli necessary to indicate deception in the examinee.
The analysis phase of the polygraph exam captures the examinee’s responses to different types of test stimuli, numerically quantifying them to calculate a categorical result for the exam. The examiner also allows the examinee to explain their physiological responses to assist in resolving inconsistencies in their answers during the test.
There are several types of polygraph exams.
Evidentiary Examinations
This test involves questioning the examinee in a pending judicial proceeding, with the purpose of introducing the polygraph results into evidence in the trial.
Paired Testing Examinations
These exams occur in tandem with two or more examinees who are questioned by independent examiners mutually blind to the test results of the other exam. These polygraphs usually regard a centrally contesting singular fact where all examinees involved in the process are expected to know the truth of the matter under questioning. The paired testing is usually a voluntary stipulation to resolve disputed facts between testifying parties in criminal or civil cases.
Investigative Examinations
These polygraph tests will assist criminal investigations where the examiner isn’t informed of the case material. The examiner doesn’t believe the exam results will be admitted to evidence in court proceedings. Investigative exams may include screening purposes or investigating known incidents or allegations.
Diagnostic Examinations
This test is an event-specific, investigative, or evidentiary polygraph that assists in determining the truthfulness of an examinee in their knowledge of an allegation or reported issue. These tests can address single aspects of events or multiple issues.
Screening Examinations
These exams occur without any reported allegation or incident, usually as pre-employment testing for candidates.
Polygraph Exam Test Data Analysis
The polygraph test data analysis involves a manual or automated structured method to evaluate the recorded physiological data from the examinee in terms of its probable margins of uncertainty concerning the examinee’s concealed knowledge, deception, or truthfulness.
The data analysis decisions for screening and diagnostic polygraph exams include the following.
Diagnostic Opinion
The examiner’s professional opinion on the polygraph exam in evidentiary testing or paired testing. The results of these exams are described by the examiner in terms of their statistical significance. After analyzing the test data, the examiner compiles their report, using the following terminology to assess the examinee’s response and performance during the polygraph test.
- Deception Indicated (DI).
- No Deception Indicated (NDI).
- Inconclusive (INC).
- No Opinion (NO).
The examiner reports test results of recognition tests with the following terms.
- Recognition Indicated (RI).
- No Recognition Indicated (NRI).
- No Opinion (NO).
Screening Opinion
The examiner’s professional opinion on the polygraph test results using the following terms.
- Significant Response (SR).
- No Significant Response (NSR).
- Inconclusive (INC).
- No Opinion (NO).
Understanding Polygraph Techniques
The polygraph exam technique consists of a combination of the following two factors.
The polygraph test format – Where there’s a published description of the polygraph exam procedures conforming to evidence-based principles for target issue selection, construction of test questions, and exam execution guidelines.
A published guideline of polygraph exam procedures conforming to evidence-based principles for target issue selection, construction of the data analyses model for the test, including its physiological features, decision rules, transformation, and standard data.
Polygraph Techniques for Evidentiary Exams
These guidelines are based on a minimum of two published scientific studies, either replicated or original, which demonstrate average accuracy ratings of 90% or more, excluding any inconclusive results which don’t exceed a rate of 20%.
Polygraph Techniques for Paired Exams
These guidelines are based on a minimum of two published scientific studies, either replicated or original, which demonstrate average accuracy ratings of 86% or more, excluding any inconclusive results which don’t exceed a rate of 20%.
Polygraph Techniques for Investigative Exams
These guidelines are based on a minimum of two published scientific studies, either replicated or original, which demonstrate average accuracy ratings of 80% or more, excluding any inconclusive results which don’t exceed a rate of 20%.
Polygraph Techniques for Screening Exams
These guidelines are based on a minimum of two published scientific studies, either replicated or original, demonstrating average accuracy ratings significantly greater than a chance result. They must involve a “successive hurdles” approach entailing additional examinee testing using validated methods when the examiner cannot resolve the screening test favorably.
Polygraph Examiner Responsibilities
The polygraph examiner must comply with all state requirements for continual education, where applicable. The examiner must complete a minimum of 30 hours of continuing education every two years involving coursework related to polygraph science.
The examiner is responsible for maintaining personal records to document they underwent this continual education and met the requirements. The examiner must represent their APA membership category accurately and their academic credentials, certification, and licensure status at all times.
The examiner must make a reasonable effort to determine if the examinee is suitable to undergo a polygraph exam. They must inquire into the examinee’s psychological and medical condition as permitted by the law.
Any physical, mental, or medical conditions in the examinee observed by the examiner or known to them must be included in the examiner’s evaluation of the examinee when conducting the test and evaluating its results.
Polygraph Instrumentation and Recordings
The examiner must ensure that all tests they conduct use properly functioning polygraph instrumentation that records the following physiological data at a minimum.
Pneumograph components record respiration patterns.
Pneumograph components separately record the following.
- Abdominal and thoracic patterns using electrodermal activity show changes in the skin’s conductance or resistance to electrical current.
- The cardiovascular activity involves pulse rate, pulse amplitude, and blood pressure changes.
A seat activity sensor to detect movement.
The examiner may record other physiological data during the test. However, they may not use this data to formulate categorical or probabilistic conclusions unless replicated and published research supports the validity of the data.
All physiological recordings during the exam must be continuous, and the amplitude of results should be easily read and interpreted by the examiner and any third-party examiner reading the results.
Polygraph Exam Locations and Testing Conditions
The polygraph testing environment must be free of distractions, allowing the examinee to focus. Examiners conducting a public viewing may not render their opinions on the examinee’s responses concerning the truthfulness of deception.
Examiners must ensure all exam reenactments are clearly conveyed to third-party viewers. If determined the reenactment is not clearly articulated, the examiner must immediately report their finding to the APA National Office.
Polygraph Exam Preparation
Before the polygraph, the examiner must take the time to discuss potential problem areas and issues with the exam.
Polygraph Pretest Best Practices
The examiner must obtain sufficient information to identify the examinee and receive informed consent from the examinee before starting the polygraph test. The examiner will obtain permission after giving the examinee an overview of the polygraph exam process, sensors and instrumentation, use of video or audio recording equipment, the issues discussed during the test, requirements for the examinee’s cooperation, and results.
The examiner must review all the test questions they intend to ask in the exam before starting the test. The examiner must conduct the test using a neutral behavior and manner and not display bias.
Polygraph Testing Best Practices
A polygraph examiner must use evidence-based validation techniques in the exam. The method used in the polygraph exam is valid if it is supported by research approved by APA standards. If there are deviations from the protocols provided by a validated polygraph technique, the examiner must explain them in writing.
Nothing in the standards of practice prevents researchers and examiners from investigating and developing improved polygraph methods. Polygraph techniques that don’t meet APA standards for validation are considered experimental methodologies.
Field examiners employing these experimental techniques must remain in compliance with laws relating to human subject research. They must inform the examinee and the client requesting the test of their intention to use experimental techniques.
The results derived from the use of experimental techniques in field settings may not be used in isolation when rendering screening or diagnostic decisions. Nothing in the standards of practice prohibits using supportive methods that don’t meet the requirements of the standard, such as “Searching Peak of Tension,” “The Yes Test,” etc.
However, any non-validated polygraph techniques cannot be used in isolation to render diagnostic or screening decisions by the examiner. Examiners must conduct acquaintance tests for any evidentiary, diagnostic, initial screening, paired testing, and investigative exams.
The questions used by the examiner in the assessment of deception and truth must be followed by minimum time intervals of 20 seconds from question to question.
Examiners must utilize standardized polygraph chart markings and take a video and audio recording of all exam phases, maintaining them as part of the exam files. These records must be consistent with regulations and, laws, agency policies for at least one year after the test date.
An APA polygraph examiner cannot conduct more than three evidentiary or four diagnostic exams in a single day and no more than five exams in a single day.
Examiners testing sex offenders as a condition of probation, treatment, supervised release, or parole must earn a certificate of training with a minimum of 40 hours of instruction in post-conviction examinations.
Polygraph Exam Scoring Best Practices
The examiner’s opinions and conclusions must be based on the decision rules and validated scoring methodologies. All the examiner’s notes must have sufficient precision and clarity so that other examiners can read and comprehend them, allowing them to replicate the examiner’s test analysis and their conclusions.
In evidentiary exams, the examiner must report the probabilistic results for the polygraph technique and the rendered opinion. Examiners cannot report or disclose the exam results until they complete their session analysis.
Examiners must maintain the confidentiality of the exam and its results until they receive a release from the client. An examiner subject to a quality control review must disclose all relevant information regarding the case under consideration.
