Pretest Interview in a Polygraph Exam: Complete Guide

Definition and Purpose

The pretest interview is the first substantive phase of any polygraph (lie detector) examination. It is the conversation that takes place between you — the examinee — and the polygraph examiner before you are connected to any instruments. Despite being labeled a "pretest," this phase is far from preliminary. It is the foundation upon which the entire examination rests.

Nakić's 2020 study within the Police Directorate of the City of Belgrade, involving 270 respondents, confirmed that issues arose during polygraph examinations when the pre-test interview was not given adequate attention [1]Verified Significance of Pre-Test Interview in Polygraph Examination
Confirms that issues arose during polygraph examinations when pre-test interviews were not given adequate attention, based on study of 270 respondents in Belgrade.. Reutskaya (2016) proposed reconceptualizing the pretest interview as a semi-formalized directional diagnostic interview that functions as the structured psychological introduction to the polygraph procedure [2]Verified Theoretical Basis of Pretest Interview the Survey on a Polygraph
Proposes reconceptualizing the pretest interview as a semi-formalized directional diagnostic interview that functions as the structured psychological introduction to the polygraph procedure..

During the pretest interview, the examiner will explain how the polygraph works, discuss the issue or issues being tested, review your background, assess your physical and psychological suitability for testing, and — critically — formulate and review every single question that will appear during the in-test (chart collection) phase [3]Verified Federal Psychophysiological Detection of Deception Examiner Handbook
Official policy manual for all federal polygraph programs standardizing testing procedures, scoring methods, and quality assurance requirements including pretest interview protocols.. No question should ever be asked on the polygraph instrument that you have not already seen, discussed, and agreed upon during this conversation. The APA Standards of Practice (effective August 23, 2024) require that "the examiner shall review all test questions prior to recording the physiological responses of the examinee" [4]Verified APA Standards of Practice (Effective August 23, 2024)
Confirms APA requirements for pretest question review, informed consent, examination recording, minimum 90-minute scheduling, and use of validated techniques..

The pretest interview has been considered an indispensable component of the polygraph examination in scientific literature for decades. The 2003 National Research Council report on polygraph testing noted that the pretest interview "shapes the expectations and emotional state of the examinee during the test" and influences physiological responses to both relevant and comparison questions [5]Verified The Polygraph and Lie Detection
Confirms that the pretest interview shapes expectations and emotional state of the examinee, that shared understanding of questions is especially important, and discusses sources of variability in test outcomes.. If you are preparing for a private lie detector test, a pre-employment screening, or a criminal defense polygraph, understanding the pretest is one of the most valuable things you can do. For an overview of the full examination process, see our guide on what to expect on the day of your polygraph test.

The Pretest Within the Four Phases of a Polygraph Exam

A complete, professionally administered polygraph examination consists of four distinct phases as outlined in the U.S. Department of Defense Federal PDD Examiner Handbook [3]Verified Federal Psychophysiological Detection of Deception Examiner Handbook
Official policy manual for all federal polygraph programs standardizing testing procedures, scoring methods, and quality assurance requirements including pretest interview protocols.:

Phase 1: Pretest Interview — the phase covered in this guide, where the examiner and examinee prepare for the test.

Phase 2: Chart Collection (In-Test) — the phase where you are connected to the polygraph instrument and the test questions are presented during multiple chart runs.

Phase 3: Data Analysis — the examiner evaluates the physiological data collected during the charts, either manually or using automated scoring algorithms.

Phase 4: Post-Test Interview — the examiner discusses the results with you and provides an opportunity for clarification or additional comment.

Of these four phases, the pretest interview is almost always the longest. In a typical 90-minute-to-3-hour examination, the pretest alone will consume 45 to 90 minutes — sometimes longer for complex multi-issue tests. The APA Standards of Practice require that examinations be scheduled for not less than 90 minutes total [4]Verified APA Standards of Practice (Effective August 23, 2024)
Confirms APA requirements for pretest question review, informed consent, examination recording, minimum 90-minute scheduling, and use of validated techniques.. For a full walkthrough of all phases, see our guide to lie detector test stages: pre-test, test and post-test explained.

It Establishes the Scientific Foundation

A polygraph measures physiological responses — changes in breathing, electrodermal activity (EDA), cardiovascular responses, and sometimes movement — that are associated with deception [3]Verified Federal Psychophysiological Detection of Deception Examiner Handbook
Official policy manual for all federal polygraph programs standardizing testing procedures, scoring methods, and quality assurance requirements including pretest interview protocols.. For these measurements to be meaningful, the examiner must ensure that every test question is clear, unambiguous, and understood in exactly the same way by both the examiner and the examinee.

The 2003 NRC report emphasized that shared understanding is especially important for polygraph questions, particularly screening polygraphs that ask about general categories of behavior, and that the pretest interview is where this shared understanding is established [5]Verified The Polygraph and Lie Detection
Confirms that the pretest interview shapes expectations and emotional state of the examinee, that shared understanding of questions is especially important, and discusses sources of variability in test outcomes.. Reutskaya (2016) reconceptualized the pretest interview as a structured psychological introduction to the polygraph procedure, emphasizing its essential scientific role rather than treating it as merely an administrative step [2]Verified Theoretical Basis of Pretest Interview the Survey on a Polygraph
Proposes reconceptualizing the pretest interview as a semi-formalized directional diagnostic interview that functions as the structured psychological introduction to the polygraph procedure..

It Reduces Errors and Improves Quality

A false positive occurs when a truthful person's test results suggest deception. One of the leading causes of false positives is ambiguous or confusing test questions. If a question can be interpreted in multiple ways, a truthful person may experience anxiety about whether they are understanding the question correctly — and that anxiety can produce physiological reactions that mimic deception.

Nakić's 2020 study confirmed that errors and omissions from earlier investigation stages could surface during the pretest interview, making it an essential quality-control checkpoint for the entire examination process [1]Verified Significance of Pre-Test Interview in Polygraph Examination
Confirms that issues arose during polygraph examinations when pre-test interviews were not given adequate attention, based on study of 270 respondents in Belgrade.. The pretest interview eliminates ambiguity by ensuring every question is perfectly clear before chart collection begins.

The APA's 2011 Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques — which examined 38 studies involving 3,723 examinations — found that event-specific (single issue) diagnostic testing produced an aggregated decision accuracy of 89%, while the combination of all validated PDD techniques produced a decision accuracy of 87% [6]Verified Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms that event-specific polygraph testing produced 89% decision accuracy and combined validated techniques produced 87% accuracy based on analysis of 3,723 examinations.. These high accuracy figures are achievable specifically when examinations are conducted in accordance with APA Standards of Practice, which require a thorough pretest interview [4]Verified APA Standards of Practice (Effective August 23, 2024)
Confirms APA requirements for pretest question review, informed consent, examination recording, minimum 90-minute scheduling, and use of validated techniques..

It Assesses Suitability for Testing

Not everyone is suitable for a polygraph exam. Certain medications, medical conditions, mental health issues, extreme fatigue, or recent intoxication can compromise results. The pretest interview is where the examiner screens for these factors [3]Verified Federal Psychophysiological Detection of Deception Examiner Handbook
Official policy manual for all federal polygraph programs standardizing testing procedures, scoring methods, and quality assurance requirements including pretest interview protocols.. The APA Standards of Practice state that the examiner should make reasonable efforts to determine that the examinee is a suitable candidate, including basic inquiries into medical and psychological condition [4]Verified APA Standards of Practice (Effective August 23, 2024)
Confirms APA requirements for pretest question review, informed consent, examination recording, minimum 90-minute scheduling, and use of validated techniques.. If you are found unsuitable for testing, you will learn this during the pretest — before any data is collected. To learn more about suitability factors, see our guide on thyroid disorders and polygraph test accuracy.

It Fulfills Ethical and Legal Requirements

The American Polygraph Association (APA) mandates that a comprehensive pretest interview be conducted for every examination. The APA Standards of Practice (effective August 23, 2024) establish specific pretest requirements including obtaining informed consent, identifying the examinee, and reviewing all test questions prior to chart collection [4]Verified APA Standards of Practice (Effective August 23, 2024)
Confirms APA requirements for pretest question review, informed consent, examination recording, minimum 90-minute scheduling, and use of validated techniques.. ASTM International standard E2062-11(2017), the Standard Guide for PDD Examination Standards of Practice, similarly establishes essential and recommended elements in procedures for the conduct of PDD examinations including pretest requirements [7]Verified ASTM E2062-11(2017) Standard Guide for PDD Examination Standards of Practice
Confirms ASTM standard establishing essential and recommended elements in procedures for the conduct of PDD examinations including pretest requirements..

Informed consent must be obtained during the pretest, which protects both your legal rights and the validity of the examination. For more on the regulatory landscape, see our overview of polygraph licensing laws across every state. Skipping or shortening the pretest is considered a violation of professional standards.

The Complete Pretest Sequence

Understanding the sequence of events during the pretest interview can dramatically reduce anxiety. While every examiner has their own professional style, the core components are consistent across examiners trained to APA standards [4]Verified APA Standards of Practice (Effective August 23, 2024)
Confirms APA requirements for pretest question review, informed consent, examination recording, minimum 90-minute scheduling, and use of validated techniques. [3]Verified Federal Psychophysiological Detection of Deception Examiner Handbook
Official policy manual for all federal polygraph programs standardizing testing procedures, scoring methods, and quality assurance requirements including pretest interview protocols..

The NRC report noted that the pretest interview typically has multiple purposes: it explains the test procedure to the examinee, explains the questions to be asked so that examiners and examinees understand the questions in the same way, shapes the expectations and emotional state of the examinee during the test, and — in comparison question testing — helps the examiner decide which comparison questions to ask [5]Verified The Polygraph and Lie Detection
Confirms that the pretest interview shapes expectations and emotional state of the examinee, that shared understanding of questions is especially important, and discusses sources of variability in test outcomes..

The typical sequence includes:

1. Introductions and environment setup 2. Explanation of the polygraph process 3. Informed consent and rights review 4. Background and medical screening 5. Discussion of relevant issues 6. Question formulation and review 7. An acquaintance or stimulation test (if applicable — the APA requires acquaintance tests for all diagnostic, evidentiary, paired-testing, initial screening, and initial investigative examinations [4]Verified APA Standards of Practice (Effective August 23, 2024)
Confirms APA requirements for pretest question review, informed consent, examination recording, minimum 90-minute scheduling, and use of validated techniques.) 8. Final review before transitioning to the in-test phase

For a detailed look at what examiners observe during this process, see our guide on what behavior a polygraph examiner looks for.

Conversational and Background Questions

During the pretest, the examiner asks conversational questions to learn about you, assess your suitability, and gather context. These are not scored by the polygraph instrument. Examples include questions about your full legal name, prior polygraph experience, current medications, sleep quality, recent substance use, medical conditions, psychological or psychiatric diagnoses, understanding of why you are there, and whether anyone is forcing you to take the test [3]Verified Federal Psychophysiological Detection of Deception Examiner Handbook
Official policy manual for all federal polygraph programs standardizing testing procedures, scoring methods, and quality assurance requirements including pretest interview protocols..

These questions serve multiple purposes. They help the examiner determine if you are suitable for testing, they begin building rapport, and they establish a baseline understanding of your communication style. Research on verbal cues to deception, such as the Model Statement protocol study by Leal, Vrij, and colleagues (2021), has shown that truth tellers and lie tellers exhibit systematically different communication patterns — knowledge that informs the examiner's assessment approach during the pretest [8]Verified Verbal Cues to Deceit When Lying Through Omitting Information: Examining the Effect of a Model Statement Interview Protocol
Found that truth tellers reported more complications than lie tellers across omission scenarios, demonstrating systematic differences in communication patterns between truthful and deceptive individuals..

Formal Test Questions Reviewed During the Pretest

The formal questions that will appear during the chart collection phase are developed during the pretest and reviewed with you in advance. There are several categories of test questions used in polygraph examinations, as described in Krapohl and Shaw's Fundamentals of Polygraph Practice [9]Verified Fundamentals of Polygraph Practice
Comprehensive polygraph textbook covering pretest interview procedures, test question construction, psychophysiology, data analysis, and evidence-based practices.:

Relevant questions — directly address the issue being tested.

Comparison questions — broader questions about past behavior, designed to elicit a physiological response in truthful examinees for comparison against relevant questions. Research by Ginton (2017) provided field evidence for the practical effectiveness of both exclusive and non-exclusive comparison questions in operational settings [10]Verified Examining Different Types of Comparison Questions in a Field Study of CQT Polygraph Technique
Field study providing evidence for the practical effectiveness of both exclusive and non-exclusive comparison questions in operational settings.. For more detail, see our guide to the directed lie test (DLT).

Irrelevant questions — neutral questions used to establish physiological baselines.

Sacrifice relevant questions — introductory relevant questions designed to absorb initial reactivity.

Symptomatic questions — questions designed to detect outside issues or unrelated fears that could contaminate results.

Every one of these questions is presented to you during the pretest. You should know exactly what you will be asked before you are ever connected to the instrument. If an examiner introduces surprise questions during the in-test phase, that is a serious violation of professional standards [4]Verified APA Standards of Practice (Effective August 23, 2024)
Confirms APA requirements for pretest question review, informed consent, examination recording, minimum 90-minute scheduling, and use of validated techniques..

What You Must Be Told

Informed consent is a fundamental ethical and legal requirement in polygraph testing. The APA Standards of Practice specify that informed consent should be obtained "after an overview of the polygraph process, including polygraph instrumentation and sensors, use of video/audio recording, issues to be discussed, requirements for cooperation during testing, and the need to report information and results to the referring professionals" [4]Verified APA Standards of Practice (Effective August 23, 2024)
Confirms APA requirements for pretest question review, informed consent, examination recording, minimum 90-minute scheduling, and use of validated techniques..

During the pretest interview, the examiner is obligated to ensure you understand that the examination is voluntary (for private and most civil tests), that you may stop at any time, that you will not be asked any surprise questions, that the examination will be audio and/or video recorded, who will receive the results, that the polygraph measures physiological responses rather than thoughts, what happens if results are inconclusive, and your right to consult an attorney before testing in legal contexts.

The examiner should provide a written consent form covering these points. If anything is unclear, ask questions — a professional examiner will welcome your questions and answer them patiently. The APA Model Policy for Relationship Polygraph Testing (adopted August 2025) further clarifies that informed consent must be obtained independently from the examinee and must clarify that participation is voluntary and can be discontinued at any time [4]Verified APA Standards of Practice (Effective August 23, 2024)
Confirms APA requirements for pretest question review, informed consent, examination recording, minimum 90-minute scheduling, and use of validated techniques.. To learn more about what happens when results are inconclusive, see our guide on retaking a polygraph after an inconclusive result.

What Happens If You Want to Stop?

You may stop the examination at any point during the pretest interview or at any point during the entire exam. For private examinations, this is an unconditional right. The examiner should not attempt to pressure you into continuing. If you experience undue pressure during the pretest, this is a significant red flag that the examiner may not be following professional standards [4]Verified APA Standards of Practice (Effective August 23, 2024)
Confirms APA requirements for pretest question review, informed consent, examination recording, minimum 90-minute scheduling, and use of validated techniques..

Principles of Good Polygraph Questions

The quality of polygraph test questions is one of the most important factors affecting exam accuracy. Norman Ansley's foundational work on question formulation, originally published in the APA journal Polygraph (Volume 27, No. 3, 1998), established specific guidelines covering relevant questions, comparison questions, irrelevant questions, and the wording of peak-of-tension tests [11]Verified Question Formulation
Foundational paper presenting observations and specific guidelines for question formulation covering relevant, comparison, and irrelevant questions in polygraph testing.. Krapohl and Shaw's Fundamentals of Polygraph Practice (2015) provides comprehensive modern coverage of test question construction principles [9]Verified Fundamentals of Polygraph Practice
Comprehensive polygraph textbook covering pretest interview procedures, test question construction, psychophysiology, data analysis, and evidence-based practices..

Key principles include:

Single issue per question — each question should address one specific behavior or event.

Behavioral language — questions should reference observable behaviors rather than mental states.

Unambiguous wording — questions should have only one possible interpretation.

Mutual understanding — both the examiner and examinee must agree on what the question means.

Time-bounded — questions should include a clear timeframe when relevant.

Answerable with yes or no — all polygraph test questions require a simple yes or no answer.

During the pretest, the examiner will typically present each question and read it to you. You will be asked if you understand the question and if you want to change any wording. This collaborative process is a hallmark of a thorough, scientifically rigorous examination.

Why Question Review Matters for Accuracy

Consider this scenario: you are asked, "Have you ever stolen anything?" That question is impossibly broad. Nearly everyone has taken something small at some point — a pen from work, an extra napkin. The anxiety of interpreting this question could trigger physiological responses in a truthful person, leading to a false positive.

A properly formulated relevant question might instead be: "Did you steal the $2,000 from the office safe on March 15, 2025?" This is specific, clear, and unambiguous. The pretest interview is where this refinement happens. Without it, the polygraph data would be unreliable.

The NRC report specifically highlighted that examinees "may believe they are lying when providing factually truthful responses, or vice versa" when questions lack clear criteria [5]Verified The Polygraph and Lie Detection
Confirms that the pretest interview shapes expectations and emotional state of the examinee, that shared understanding of questions is especially important, and discusses sources of variability in test outcomes.. This is precisely why single-issue test formats — which focus the pretest on one clearly defined topic — tend to achieve higher accuracy than multi-issue formats. The APA's meta-analysis confirmed that event-specific (single-issue) tests produced 89% decision accuracy compared to 85% for multi-issue tests [6]Verified Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms that event-specific polygraph testing produced 89% decision accuracy and combined validated techniques produced 87% accuracy based on analysis of 3,723 examinations..

Why Rapport Matters

The relationship between examiner and examinee directly affects physiological responses during testing. The NRC report noted that the pretest interview is where the atmosphere of the examination is established, and that examiner training provides instruction on the kind of atmosphere that is to be created during this phase [5]Verified The Polygraph and Lie Detection
Confirms that the pretest interview shapes expectations and emotional state of the examinee, that shared understanding of questions is especially important, and discusses sources of variability in test outcomes.. A skilled examiner will put you at ease while maintaining professional boundaries.

The pretest interview is not an interrogation. It is a structured professional conversation designed to ensure you understand the process, feel comfortable enough to produce reliable physiological data, and are fully informed about what to expect. The examiner's goal is clarity and cooperation — not intimidation.

Nakić's 2020 research emphasized that the examiner uses the pretest to evaluate the basic pattern of the examinee's behavior, explore their familiarity with the matter under investigation, and assess their understanding of how the polygraph works [1]Verified Significance of Pre-Test Interview in Polygraph Examination
Confirms that issues arose during polygraph examinations when pre-test interviews were not given adequate attention, based on study of 270 respondents in Belgrade.. Recent research on facial thermal cues in deception detection, such as Hypšová and colleagues' 2025 study, has also demonstrated that cognitive load and emotional state produce measurable physiological signatures — reinforcing why establishing a calm, controlled pretest environment is so important for accurate results [12]Verified Unveiling Faking in Job Interviews by Examining Facial Thermal Cues in Deception Detection
Found that nasal temperature was higher in rehearsed responses than spontaneous responses and in spontaneous lies than truths, suggesting cognitive load and emotional state produce measurable physiological signatures..

Duration by Examination Type

The APA Standards of Practice require that examinations be scheduled for not less than 90 minutes total [4]Verified APA Standards of Practice (Effective August 23, 2024)
Confirms APA requirements for pretest question review, informed consent, examination recording, minimum 90-minute scheduling, and use of validated techniques.. Within this timeframe, the pretest interview typically consumes the largest share:

Simple single-issue private test (e.g., infidelity): 30 to 45 minutes for the pretest.

Standard specific-issue diagnostic test: 45 to 60 minutes.

Complex multi-issue screening (e.g., pre-employment for law enforcement): 60 to 90 minutes or longer. For an example, see our guide on the U.S. Marshals Service polygraph exam process.

Post-conviction sex offender testing (PCSOT): Can extend the pretest considerably due to specialized requirements.

If an examiner rushes through the pretest in under 20 minutes, this is a red flag. A comprehensive pretest takes time because it must cover consent, medical screening, background discussion, issue review, and question formulation — all of which are required by professional standards.

The Link Between Pretest Quality and Test Outcomes

The 2003 NRC report identified several sources of variability in polygraph test outcomes, noting that accuracy "may vary with a number of factors, such as the population of examinees, characteristics of individual examinees or examiners, relationships established in the interview, testing methods, and the use of countermeasures" [5]Verified The Polygraph and Lie Detection
Confirms that the pretest interview shapes expectations and emotional state of the examinee, that shared understanding of questions is especially important, and discusses sources of variability in test outcomes.. Most polygraph testing procedures allow for uncontrolled variation in test administration — including the creation of the emotional climate and question selection — that can affect the level of accuracy achieved [5]Verified The Polygraph and Lie Detection
Confirms that the pretest interview shapes expectations and emotional state of the examinee, that shared understanding of questions is especially important, and discusses sources of variability in test outcomes..

A comprehensive 2021 meta-analysis by Honts and colleagues, published in Applied Cognitive Psychology, analyzed 138 datasets of comparison question polygraph tests and found that psychophysiological deception detection works similarly across laboratory and field settings [13]Verified A Comprehensive Meta-Analysis of the Comparison Question Polygraph Test
Confirms that multiple reviews of polygraph accuracy generally produced overall accuracy estimates exceeding 85% and that psychophysiological deception detection works similarly in experiments and field settings.. Multiple reviews over the years have generally produced overall accuracy estimates exceeding 85% for properly conducted examinations [13]Verified A Comprehensive Meta-Analysis of the Comparison Question Polygraph Test
Confirms that multiple reviews of polygraph accuracy generally produced overall accuracy estimates exceeding 85% and that psychophysiological deception detection works similarly in experiments and field settings..

The pretest interview is the primary mechanism by which examiners control many of the variables that influence accuracy. When examiners invest adequate time in the pretest to ensure question clarity, assess suitability, and establish appropriate rapport, the resulting examination data is cleaner and more interpretable. Horvath and Reid's seminal 1971 reliability study found high inter-rater reliability for experienced examiners using structured scoring methods — but this reliability depends on the quality of the data being scored, which in turn depends on a properly conducted pretest [14]Verified The Reliability of Polygraph Examiner Diagnosis of Truth and Deception
Seminal reliability study examining agreement among polygraph examiners interpreting the same charts, finding high inter-rater reliability for experienced examiners using structured scoring methods.. Similarly, Raskin and colleagues' 1988 NIJ-funded field study demonstrated that CQT accuracy exceeded 90% when properly employed by skilled examiners [15]Verified A Study of the Validity of Polygraph Examinations in Criminal Investigation
Major NIJ-funded field study demonstrating that CQT accuracy exceeded 90% when properly employed by skilled examiners in actual criminal investigations., and Barland and Raskin's 1976 study established baseline accuracy data that would be referenced in every subsequent government review [16]Verified Validity and Reliability of Polygraph Examinations of Criminal Suspects
One of the earliest rigorous field studies of the CQT with criminal suspects, establishing baseline accuracy data referenced in every subsequent government review..

Audio and Video Recording Standards

The APA Standards of Practice mandate — not merely recommend — that "an audio or audio-video recording of all phases of the exam shall be maintained as part of the examination files, consistent with agency policy, regulation or law, for a minimum of one (1) year" [4]Verified APA Standards of Practice (Effective August 23, 2024)
Confirms APA requirements for pretest question review, informed consent, examination recording, minimum 90-minute scheduling, and use of validated techniques.. This includes the pretest interview.

Recording the pretest serves several important purposes: it creates a verifiable record that informed consent was obtained, it documents that all test questions were reviewed with the examinee, it provides evidence of the examiner's professional conduct, and it enables quality assurance review by supervising examiners. The APA standards further require that all polygraph reports, test questions, data, recordings, and related documents be maintained for a minimum of three years [4]Verified APA Standards of Practice (Effective August 23, 2024)
Confirms APA requirements for pretest question review, informed consent, examination recording, minimum 90-minute scheduling, and use of validated techniques.. For more about instrument standards, see our article on polygraph sensor calibration and manufacturer standards.

Warning Signs to Watch For

A professionally conducted pretest should leave you feeling informed and prepared. Warning signs of an inadequate pretest include:

The pretest takes less than 20 minutes — this is insufficient time to cover all required elements.

No informed consent form is provided or discussed.

The examiner does not explain how the polygraph instrument works.

Test questions are not reviewed with you before the in-test phase.

You are told you cannot stop the test once it begins.

The examiner appears to be rushing or expresses bias about the outcome.

No audio or video recording is being made of the examination.

The examiner uses accusatory language or treats the pretest as an interrogation.

If you encounter any of these issues, you have the right to stop the examination and seek a qualified examiner. The APA maintains a directory of member examiners who are bound by its Standards of Practice [4]Verified APA Standards of Practice (Effective August 23, 2024)
Confirms APA requirements for pretest question review, informed consent, examination recording, minimum 90-minute scheduling, and use of validated techniques..

Key Differences Between the Three Phases

Understanding how the three main phases of a polygraph examination differ helps you prepare for each:

Pretest Interview (Phase 1): No instruments attached. Conversational format. All questions are developed and reviewed. Consent obtained. Medical screening completed. Typically 45 to 90 minutes.

In-Test / Chart Collection (Phase 2): Polygraph sensors attached (measuring respiration, EDA, cardiovascular activity, and movement). Questions asked in a specific sequence. Multiple chart runs conducted. You answer only "yes" or "no." Typically 20 to 45 minutes. To learn more about what EDA measures during this phase, see our guide on electrodermal activity in polygraph testing.

Post-Test Interview (Phase 3): Instruments removed. The examiner may discuss observations or preliminary findings. You may be asked to clarify or elaborate on responses. In some cases, the examiner may conduct additional chart runs if initial data requires clarification.

The pretest interview directly determines the quality of data collected in the in-test phase. As Nakić's research confirmed, insufficient pretest preparation leads to examination problems and potential errors [1]Verified Significance of Pre-Test Interview in Polygraph Examination
Confirms that issues arose during polygraph examinations when pre-test interviews were not given adequate attention, based on study of 270 respondents in Belgrade.. Japan's use of the Concealed Information Test (CIT), as documented by Hira and Furumitsu (2002), demonstrates how different testing methodologies also require extensive pretest preparation to formulate appropriate recognition questions [17]Verified Polygraphic Examinations in Japan: Application of the Guilty Knowledge Test
Documented Japan's unique use of the CIT as the only polygraph method used in criminal investigations, providing extensive real-world data on field CIT application and pretest preparation requirements..

Practical Preparation Tips

You do not need to do anything special to "prepare" for a polygraph pretest — but understanding what to expect can significantly reduce anxiety and improve your experience:

Get adequate sleep the night before your examination. Fatigue can affect physiological baseline readings.

Avoid excessive caffeine or alcohol before the test. These substances can alter your physiological responses and may affect the examiner's ability to interpret your data. See our discussion of spontaneous fluctuation rates for more on baseline physiological signals.

Bring any required documentation, including identification and any paperwork provided by the referring party.

Be prepared to disclose medications you are currently taking. This information helps the examiner assess your suitability for testing.

Arrive on time. Late arrivals can create stress that affects your baseline physiological state.

Remember that you may ask questions at any point during the pretest. If something is unclear, say so — the examiner needs you to fully understand every test question.

Understand that the pretest is collaborative, not adversarial. The examiner's goal is to create the conditions for the most accurate test possible, which requires your active participation.

If you are taking the test for legal purposes, consult with your attorney beforehand about what to expect. For language considerations, see our guide on interpreter protocols in polygraph testing.