Relevant Questions in Polygraph Testing: Complete Guide

The Question That Matters Most

A relevant question in polygraph testing is the question that directly targets the issue, allegation, or concern that prompted the examination. Unlike other question types used in the test, relevant questions address the specific behavior under investigation. For example, if someone is being tested regarding a theft from their workplace, a relevant question might be: "Did you take the missing $5,000 from the office safe?" If a spouse is being tested regarding infidelity, a relevant question might be: "Since our marriage, have you had sexual contact with anyone other than your spouse?"

The entire architecture of a polygraph examination revolves around the relevant question. Every other question in the test exists to provide a physiological comparison point against which the examinee's response to the relevant question is measured. As Gordon and Fleisher (2019) established, all polygraph techniques utilize distinct question categories — each serving a specific purpose [1]Verified Question Formulation: Irrelevant, Relevant, and Comparison Questions
Establishes that all polygraph techniques utilize four question categories with principles including yes/no format, single-issue focus, and avoidance of legal terminology. The examiner measures the relative magnitude of physiological response to the relevant question compared to the response to a comparison question. The APA's 2011 Meta-Analytic Survey of Criterion Accuracy confirmed that validated techniques using properly formulated questions produced an aggregated decision accuracy of 89% for event-specific diagnostic testing (confidence interval 83%–95%) across 38 qualifying studies [2]Verified APA Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms 89% accuracy for event-specific diagnostic polygraph techniques (CI 83-95%), 85% for screening (CI 77-93%), and 87% overall across 38 studies. This comparison-based approach is what gives polygraph testing its diagnostic power.

If a truthful person is asked a relevant question about something they did not do, their physiological response should be smaller than their response to a carefully designed comparison question. Conversely, a deceptive person will typically show a stronger physiological reaction to the relevant question because it addresses the actual issue they are trying to conceal. Research by Horowitz, Kircher, Honts, and Raskin (1997) provided empirical support for this mechanism, finding that comparison questions produced different physiological patterns for innocent versus guilty subjects in a mock crime study with 120 participants [3]Verified The Role of Comparison Questions in Physiological Detection of Deception
Mock crime study with 120 participants showing comparison questions produced different physiological patterns for innocent vs. guilty subjects. To learn more about how a full examination works, see our complete guide to lie detector tests.

Why the Relevant Question Carries So Much Weight

Understanding the importance of the relevant question requires understanding how the autonomic nervous system responds to psychological stimuli. When a person is confronted with a question about a behavior they are trying to hide, the brain recognizes the threat. This recognition triggers measurable changes in breathing patterns, electrodermal activity (skin conductance), and cardiovascular activity.

These physiological changes are not something the examinee can easily control. The fight-or-flight response operates largely below conscious awareness, which is precisely why polygraph testing works as a diagnostic tool. The relevant question acts as the trigger for this response in deceptive examinees. To understand common factors that can interfere with physiological readings, see our guide on 5 things that contaminate polygraph exam results.

Avital Ginton's Relevant Issue Gravity (RIG) framework provides a sophisticated theoretical explanation for this mechanism. Introduced in 2009 and published in Polygraph, 38(3), the RIG theory proposes that examinees who lie on relevant questions are psychologically attached to the relevant issue in a fundamentally different way than truth-tellers [4]Verified Relevant Issue Gravity (RIG) Strength: A New Concept in PDD
Introduced the RIG concept proposing that the psychological weight of relevant questions influences CQT accuracy through differential attention binding. Deceptive examinees have a stronger "gravitational pull" toward the relevant issue, making it harder for comparison questions to divert their attention — whereas truthful examinees can more easily shift their psychological focus to the comparison questions [5]Verified Examining Different Types of Comparison Questions in a Field Study of CQT Polygraph Technique
Field study comparing different types of comparison questions in real criminal investigations, providing evidence for practical effectiveness of both exclusive and non-exclusive comparison questions. This framework reframes the CQT theory by emphasizing differential attention binding rather than simple threat perception.

Notably, research by Richard O. Arther published in The Journal of Criminal Law, Criminology, and Police Science (1955) demonstrated that innocent examinees can show blood pressure elevations on relevant questions due to anxiety about false accusation — a finding that highlights the importance of proper question formulation and the comparison question framework in distinguishing innocent arousal from deceptive responses [6]Verified Blood Pressure Rises on Relevant Questions in Lie Detection: Sometimes an Indication of Innocence Not Guilt
Demonstrates that innocent examinees can show blood pressure elevations on relevant questions due to anxiety about false accusation.

Understanding the Complete Question Framework

To fully understand relevant questions, you need to understand the two other primary question types they interact with during every polygraph examination. Together, these three question types form the diagnostic framework that examiners use to reach a determination of truthful, deceptive, or inconclusive [1]Verified Question Formulation: Irrelevant, Relevant, and Comparison Questions
Establishes that all polygraph techniques utilize four question categories with principles including yes/no format, single-issue focus, and avoidance of legal terminology.

Relevant Questions directly address the specific issue under investigation. Example: "Did you steal the $5,000 from the company safe?" These are the questions the examiner is testing. Typically 2-4 are used per chart.

Comparison Questions address broader, more general behaviors not related to the specific incident. Example: "Before this year, did you ever take something that didn't belong to you?" These are designed to provoke a response in truthful examinees and are also called "control questions." Honts, Thurber, and Handler's 2021 comprehensive meta-analysis of the Comparison Question Test — the largest meta-analysis ever conducted on the CQT, analyzing 138 independent datasets — confirmed that the comparison question technique yields a significant meta-analytic effect size (d = 0.69), with an estimated AUC of 0.91, and that motivation level had a positive linear relationship with accuracy [7]Verified A Comprehensive Meta-Analysis of the Comparison Question Polygraph Test
The largest meta-analysis of the CQT, analyzing 138 datasets with effect size of 0.69 and AUC of 0.91. Found motivation level has positive linear relationship with accuracy and no publication bias. Research by Honts (1999) further showed that between-chart discussion of comparison questions significantly improved CQT accuracy, a procedural refinement that became standard practice [8]Verified The Discussion of Comparison Questions Between List Repetitions Is Associated with Increased Test Accuracy
Demonstrated that between-chart discussion of comparison questions significantly improved CQT accuracy, becoming standard practice.

Irrelevant Questions are neutral questions that should not provoke any meaningful physiological response. Example: "Are you sitting down right now?" or "Is today Wednesday?" These are used to establish a physiological resting baseline between relevant and comparison questions. Research by Hu, Hegman, Landry, and Rosenfeld (2012) demonstrated that increasing irrelevant stimuli in P300-based protocols improved the ability to detect countermeasure use, underscoring how each question type plays a role in the overall examination framework [9]Verified Increasing Irrelevant Stimuli Increases Ability to Detect Countermeasures
Found that increasing irrelevant stimuli in P300-based CIT improved ability to detect countermeasure use.

How These Three Types Work Together

The polygraph detects physiological changes associated with the psychological stress of deception. The three question types create a controlled experiment within each chart collection:

Irrelevant questions create a physiological "floor" — the minimum level of arousal expected when answering a non-threatening question. Comparison questions create a controlled stimulus that should be more psychologically threatening to a truthful person than the relevant question. Relevant questions create the primary diagnostic stimulus — a deceptive person's response to these questions should be significantly larger than their response to comparison questions.

Shull and Crowe (1993) found that different methods of comparing relevant and control question responses produce different outcomes, underscoring the importance of standardized comparison methodology [10]Verified Effects of Two Methods of Comparing Relevant and Control Questions on the Accuracy of Psychophysiological Detection of Deception
Confirms that different methods of comparing relevant and control question responses produce different diagnostic outcomes. The Honts et al. (2021) meta-analysis further confirmed that no publication bias was detected in CQT research, strengthening confidence in the question framework's validity [7]Verified A Comprehensive Meta-Analysis of the Comparison Question Polygraph Test
The largest meta-analysis of the CQT, analyzing 138 datasets with effect size of 0.69 and AUC of 0.91. Found motivation level has positive linear relationship with accuracy and no publication bias.

The examiner evaluates the polygraph data by comparing the magnitude and pattern of physiological responses across these question categories. This is why the precise wording of relevant questions is critically important — if a relevant question is vague or confusing, it may trigger an emotional response in a truthful person for reasons unrelated to deception, leading to a false positive result. For a deeper understanding of scoring methodology, see our guide on numerical scoring in polygraph examinations. To understand how many chart presentations are required, see how many chart runs a polygraph exam requires.

The Art and Science of Question Design

Relevant question formulation is one of the most critical skills a polygraph examiner must master. A poorly worded question can undermine the entire examination, regardless of how advanced the equipment is. The American Polygraph Association (APA) Standards of Practice dedicate significant attention to this topic because it is so consequential for test outcomes [11]Verified APA Standards of Practice
Establishes professional standards for polygraph examination conduct including question formulation requirements and pre-test review procedures.

The process begins during the pre-test interview, which typically constitutes the longest phase of a polygraph examination. During this phase, the examiner gathers detailed information about the issue under investigation, discusses the allegations or concerns with the examinee, and collaboratively develops the relevant questions that will be used during chart collection. For examinations involving a single-issue polygraph test, the formulation process is particularly focused.

Several fundamental principles guide this formulation process:

Single-issue focus: Each relevant question should address one and only one specific behavior or event. Compound questions that ask about multiple behaviors simultaneously are prohibited because they create diagnostic ambiguity [1]Verified Question Formulation: Irrelevant, Relevant, and Comparison Questions
Establishes that all polygraph techniques utilize four question categories with principles including yes/no format, single-issue focus, and avoidance of legal terminology.

Behavioral anchoring: Questions must reference observable, specific behaviors rather than thoughts, feelings, intentions, or knowledge. "Did you take the money?" is behaviorally anchored. "Do you know who took the money?" is not, because knowledge is a mental state rather than a behavior.

Clear temporal boundaries: Relevant questions should define a clear time period when applicable. "Since January 2024, have you used any illegal drugs?" is properly bounded. "Have you ever used drugs?" is too broad.

Answerable with yes or no: Every relevant question must be structured to permit a definitive yes or no response. Open-ended or ambiguous phrasing creates physiological noise that contaminates scoring [1]Verified Question Formulation: Irrelevant, Relevant, and Comparison Questions
Establishes that all polygraph techniques utilize four question categories with principles including yes/no format, single-issue focus, and avoidance of legal terminology.

Mutual understanding: Both the examiner and the examinee must agree on the exact meaning of every word in the question before testing begins. If there is any ambiguity, the question must be rephrased until both parties share the same understanding.

Raymond Nelson's Contributions to Question Formulation Science

Raymond Nelson, a past president of the American Polygraph Association and research specialist with Lafayette Instrument Company, has published extensively on question formulation and test data analysis [12]Verified Polygraph Questions and Questionable Questions
Published research by Raymond Nelson on polygraph question formulation principles and practices. His published works include "Polygraph Questions and Questionable Questions" in the APA Magazine (July/August 2015), and he co-presented "Test Question Formulation: What We Know, What We Think We Know, and What We Pretend to Know" with co-researcher Mark Handler at APA conferences [13]Verified AFMGQT Format Report - APA Research Committee
APA Research Committee report examining generalizability of knowledge regarding event-specific test formats with two or three relevant questions. Nelson has published numerous studies covering all aspects of polygraph testing, including interviewing, question formation, and test target selection [12]Verified Polygraph Questions and Questionable Questions
Published research by Raymond Nelson on polygraph question formulation principles and practices.

Nelson's 2015 review article, "Scientific Basis for Polygraph Testing," published in Polygraph, 44(1), 28-61, confirmed that event-specific diagnostic polygraphs provide a mean accuracy of.89 with a 95% confidence range from.83 to.95 [14]Verified Scientific Basis for Polygraph Testing
Confirms event-specific diagnostic polygraph accuracy of.89 (CI.83 to.95) and screening accuracy of.85 (CI.77 to.93). This comprehensive review summarized the literature for all aspects of the testing procedure including the pretest interview, test data collection, and test data analysis.

Nelson's work on the scientific analytic theory of polygraph testing holds that greater changes in physiology will be loaded at different types of test stimuli (relevant and comparison questions) as a function of deception or truth-telling. This theoretical framework underscores why precise question formulation is not merely a matter of protocol compliance but a fundamental determinant of test validity.

The Pre-Test Review Process

One of the most important protections for examinees is the pre-test question review. APA Standards of Practice require that every question to be used during chart collection — including all relevant questions — be reviewed word for word with the examinee before any sensors are attached [11]Verified APA Standards of Practice
Establishes professional standards for polygraph examination conduct including question formulation requirements and pre-test review procedures.

This serves multiple purposes: It ensures the examinee fully understands what they are being asked and can provide an informed, unambiguous response. It gives the examinee an opportunity to raise concerns, request clarifications, or disclose information that might affect question wording. It eliminates the possibility of surprise questions during testing, which could trigger emotional reactions unrelated to deception and contaminate results. It also establishes a documented record that the examinee consented to the questions as worded, which is important for legal defensibility.

If you are preparing for a polygraph test, knowing that you will see every question before the test begins should provide reassurance. Any examiner who refuses to show you the questions in advance, or who claims that surprise questions are part of their methodology, is violating established professional standards. The Employee Polygraph Protection Act of 1988 (EPPA) further protects examinees by establishing specific rights during all testing phases, including the pretest [15]Verified Employee Polygraph Protection Act of 1988
Federal law prohibiting most private employers from using polygraph tests with limited exceptions and strict procedural requirements. Understanding the differences between private and court-ordered polygraphs can also help you know what to expect.

Professional Standards That Govern Every Word

The APA Standards of Practice provide detailed guidance on how relevant questions must be constructed. These standards exist because decades of research have demonstrated that question quality directly impacts test accuracy. The APA's 2011 Meta-Analytic Survey found that validated techniques using properly formulated questions produced an aggregated decision accuracy of 89% for event-specific diagnostic testing (confidence interval 83%-95%) and 85% for multi-issue screening (confidence interval 77%-93%) [2]Verified APA Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms 89% accuracy for event-specific diagnostic polygraph techniques (CI 83-95%), 85% for screening (CI 77-93%), and 87% overall across 38 studies. The combination of all validated PDD techniques produced a decision accuracy of 87% (confidence interval 80%-94%) with an inconclusive rate of 13% [2]Verified APA Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms 89% accuracy for event-specific diagnostic polygraph techniques (CI 83-95%), 85% for screening (CI 77-93%), and 87% overall across 38 studies. Nelson's 2015 update confirmed these findings, reporting a mean accuracy of.89 with a 95% confidence range from.83 to.95 for event-specific diagnostic polygraphs [14]Verified Scientific Basis for Polygraph Testing
Confirms event-specific diagnostic polygraph accuracy of.89 (CI.83 to.95) and screening accuracy of.85 (CI.77 to.93).

The key requirements from the APA standards include:

Simplicity: Questions should use the simplest language possible. Technical jargon, legal terminology, or complex sentence structures must be avoided. The question should be immediately comprehensible to anyone with a basic command of the language.

Specificity: Questions must be specific enough to address one discrete behavior or event. "Did you steal from the company?" is less precise than "Did you take the $2,000 reported missing from Register 3 on March 15?"

No compound structures: Questions must not join two or more allegations with "and" or "or." The question "Did you steal the money or help someone else steal it?" contains two separate allegations and cannot be answered with a single yes or no if only one is true.

No assumptive language: Questions should not assume facts not in evidence. "After you took the money, did you spend it on drugs?" assumes the theft occurred.

Culturally appropriate language: Examiners must consider the examinee's educational background, cultural context, and language proficiency when choosing words.

These standards are further reinforced by ASTM International standards developed under Committee E52 on Forensic Psychophysiology, which was formed in 1996 [16]Verified ASTM E2062 Standard Guide for PDD Examination Standards of Practice
ASTM International technical standard establishing essential elements for polygraph examination procedures under Committee E52. Key standards include ASTM E2062 (Standard Guide for PDD Examination Standards of Practice), which establishes essential and recommended elements in PDD examination procedures [16]Verified ASTM E2062 Standard Guide for PDD Examination Standards of Practice
ASTM International technical standard establishing essential elements for polygraph examination procedures under Committee E52, and ASTM E2031 (Standard Practice for Quality Control of PDD Examinations), which ensures polygraph tests meet proper quality control criteria [17]Verified ASTM E2031 Standard Practice for Quality Control of PDD Examinations
Establishes essential and recommended procedures for quality control of polygraph examinations. Additional standards include ASTM E2229 (Standard Practices for Interpretation of PDD Data) and ASTM E1954 (Standard Practice for Conduct of Research in PDD) [16]Verified ASTM E2062 Standard Guide for PDD Examination Standards of Practice
ASTM International technical standard establishing essential elements for polygraph examination procedures under Committee E52.

Behavioral Descriptions vs. Mental State Questions

One of the most nuanced aspects of relevant question formulation involves the distinction between behavioral descriptions and mental state questions. Professional consensus and published research support the principle that questions targeting specific, observable behaviors produce more reliable physiological data than questions targeting internal mental states [1]Verified Question Formulation: Irrelevant, Relevant, and Comparison Questions
Establishes that all polygraph techniques utilize four question categories with principles including yes/no format, single-issue focus, and avoidance of legal terminology [16]Verified ASTM E2062 Standard Guide for PDD Examination Standards of Practice
ASTM International technical standard establishing essential elements for polygraph examination procedures under Committee E52.

Consider the difference: "Did you fire the gun at John Smith on January 5?" — This references a specific, observable action. "Did you intend to harm John Smith?" — This references an internal psychological state that may be difficult to define or verify.

While there are situations where mental state questions may be necessary — particularly in screening examinations where no specific incident exists, or in PCSOT sexual history examinations — the general principle is that behaviorally anchored questions produce cleaner data and more defensible results. Understanding the differences between diagnostic and screening polygraphs helps clarify when each approach is appropriate.

Ginton's RIG framework provides additional insight into why behavioral questions tend to perform better. When a relevant question describes a specific action the examinee actually performed, the psychological gravity of that issue is heightened, producing stronger differential responses that are easier to detect and score [4]Verified Relevant Issue Gravity (RIG) Strength: A New Concept in PDD
Introduced the RIG concept proposing that the psychological weight of relevant questions influences CQT accuracy through differential attention binding. Ginton's 2017 field study examining different types of comparison questions in real criminal investigations provided evidence for the practical effectiveness of both exclusive and non-exclusive comparison questions in operational settings [5]Verified Examining Different Types of Comparison Questions in a Field Study of CQT Polygraph Technique
Field study comparing different types of comparison questions in real criminal investigations, providing evidence for practical effectiveness of both exclusive and non-exclusive comparison questions.

Criminal Investigation Examples

In criminal investigations, relevant questions are typically the most specific and narrowly tailored. Examples include:

"Did you fire the weapon at [victim's name] on [date]?" — Specific action, specific victim, specific time. "Did you take the cash from the register at [business name] on [date]?" — Behaviorally anchored theft allegation. "Were you inside the building at [address] after midnight on [date]?" — Presence at a crime scene.

Notice that each question targets a single, observable behavior within a defined time frame. These kinds of precise formulations contributed to the 89% accuracy rate observed in the APA's meta-analysis of event-specific diagnostic techniques [2]Verified APA Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms 89% accuracy for event-specific diagnostic polygraph techniques (CI 83-95%), 85% for screening (CI 77-93%), and 87% overall across 38 studies. To see how polygraphs have been used in real criminal cases, explore our analysis of polygraph testing on Forensic Files episodes.

Workplace and EPPA Investigation Examples

Under the Employee Polygraph Protection Act (EPPA), workplace polygraph examinations are heavily regulated and limited to specific circumstances, primarily involving economic loss investigations [15]Verified Employee Polygraph Protection Act of 1988
Federal law prohibiting most private employers from using polygraph tests with limited exceptions and strict procedural requirements. Relevant questions in this context must be directly tied to the specific incident:

"Did you take the missing inventory from the warehouse between January 1 and February 15?" "Did you access the company's financial system without authorization on [date]?" "Did you share confidential client data with anyone outside the company?"

EPPA requires that the employer provide specific information about the incident under investigation and that the examinee had access to the property or information in question. Learn more about employee rights relating to lie detector tests.

Relationship and Private Examination Examples

Private polygraph examinations — often requested by individuals to resolve relationship concerns — require equally careful question formulation:

"Since our marriage, have you had sexual contact with anyone other than your spouse?" "Since [date], have you sent romantic or sexual messages to anyone other than your partner?" "Have you gambled with family money since [date]?"

These questions address specific behaviors within defined time frames. For those exploring whether a lie detector can assess emotional fidelity, our guide on whether a lie detector can prove emotional cheating discusses the challenges of formulating questions for non-physical behaviors. Some couples even pursue annual polygraph tests to maintain trust.

PCSOT and Sex Offender Monitoring Examples

Post-Conviction Sex Offender Testing (PCSOT) uses relevant questions to monitor compliance with supervision conditions and treatment progress. These examinations often use questions addressing both specific behaviors and broader compliance:

"Since your last polygraph examination, have you had unsupervised contact with any minor?" "Since [date], have you viewed any sexually explicit material involving minors?"

PCSOT examinations require specialized training and a strong therapeutic alliance between the examiner, treatment provider, and supervising officer. The relevant questions must be developed collaboratively with the treatment team to address the most significant risk factors.

Errors That Undermine Test Validity

Even experienced examiners can make question formulation errors that compromise test validity. Understanding these common mistakes is essential for both examiners and consumers who want to ensure their examination is conducted properly.

Compound questions remain the most frequent error. A question like "Did you take the money or help someone else take it?" actually contains two separate allegations. An examinee who helped someone else but did not personally take the money would struggle to answer truthfully with a simple "yes" or "no," potentially producing physiological confusion that contaminates the test data.

Vague temporal boundaries create similar problems. "Have you ever stolen anything?" is so broad that virtually anyone could show an elevated response based on childhood memories or trivial incidents, making it useless for diagnostic purposes.

Legal jargon introduces ambiguity because different people may interpret legal terms differently. "Did you commit larceny?" is far less effective than "Did you take the laptop from the office?"

Emotionally loaded language can trigger responses unrelated to deception. "Did you brutally assault your neighbor?" is less diagnostically clean than "Did you strike your neighbor on [date]?" The word "brutally" adds an emotional valence that may provoke a response in truthful examinees who find the allegation itself disturbing.

Knowledge-based questions such as "Do you know who committed the theft?" target a mental state (knowledge) rather than a behavior. A person could show an elevated response to this question because they suspect someone, even if they have no definitive knowledge — making it unreliable for deception detection.

If you believe your polygraph examination included poorly formulated questions, our guide on what to do if you received inaccurate polygraph results provides important guidance.

How Different Validated Techniques Use Relevant Questions

While the fundamental role of relevant questions remains consistent across all comparison question techniques, different validated polygraph formats structure the placement and number of relevant questions differently.

The Zone Comparison Test (ZCT) typically uses three relevant questions arranged in "zones" alongside corresponding comparison questions. This format allows the examiner to evaluate each relevant question both independently and in the context of its paired comparison question.

The Air Force Modified General Question Technique (AFMGQT) uses two or three relevant questions and has been extensively studied by Nelson, Handler, and colleagues. Their APA Research Committee report examined the generalizability of scientific knowledge regarding event-specific test formats with two or three relevant questions [13]Verified AFMGQT Format Report - APA Research Committee
APA Research Committee report examining generalizability of knowledge regarding event-specific test formats with two or three relevant questions.

The Federal Zone Comparison Technique uses a specific question sequence described in the Federal Examiner Handbook, with relevant questions positioned to optimize the comparison process.

Ginton's 2017 field study found that both exclusive and non-exclusive comparison questions produced comparable accuracy rates in real criminal investigations, demonstrating that the comparison question framework is robust across different implementations [5]Verified Examining Different Types of Comparison Questions in a Field Study of CQT Polygraph Technique
Field study comparing different types of comparison questions in real criminal investigations, providing evidence for practical effectiveness of both exclusive and non-exclusive comparison questions. Similarly, Amsel's 1999 Israeli field study comparing exclusive versus non-exclusive comparison question formats found both produced comparable accuracy rates in real criminal investigations [18]Verified Exclusive or Nonexclusive Comparison Questions: A Comparative Field Study
Israeli field study finding both exclusive and non-exclusive comparison question formats produced comparable accuracy rates in real criminal investigations.

Research by Honts, Raskin, and Kircher (1992) challenged the assumption that "yes" answers to control questions reduce test accuracy, finding no significant accuracy difference between yes and no answers — dispelling a widely held examiner belief [19]Verified Effectiveness of Control Questions Answered 'Yes': Dispelling a Polygraph Myth
Found no significant accuracy difference between yes and no answers to control questions, dispelling a widely held examiner belief.

From Physiological Data to Diagnostic Decisions

After chart collection, the examiner scores the physiological data by systematically comparing the examinee's responses to relevant questions against their responses to comparison questions. This process follows standardized numerical scoring protocols that have been validated through extensive research.

For each physiological channel — respiration, electrodermal activity, and cardiovascular activity — the examiner assigns a numerical value reflecting whether the response to the relevant question was larger, smaller, or approximately equal to the response to the paired comparison question. These scores are then totaled across all charts and channels to produce a grand total score. Learn more about how this works in our detailed guide to numerical scoring in polygraph.

The APA's 2011 meta-analysis confirmed that when these standardized scoring methods are applied to validated techniques, the resulting accuracy rates are strong — with event-specific diagnostic testing achieving 89% accuracy (CI 83%-95%) [2]Verified APA Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms 89% accuracy for event-specific diagnostic polygraph techniques (CI 83-95%), 85% for screening (CI 77-93%), and 87% overall across 38 studies. The Honts et al. (2021) meta-analysis, which analyzed 138 datasets, found an effect size converting to an AUC of 0.91 when including inconclusive outcomes [7]Verified A Comprehensive Meta-Analysis of the Comparison Question Polygraph Test
The largest meta-analysis of the CQT, analyzing 138 datasets with effect size of 0.69 and AUC of 0.91. Found motivation level has positive linear relationship with accuracy and no publication bias.

Shull and Crowe's (1993) research at the Department of Defense Polygraph Institute demonstrated that different methods of comparing relevant and control question responses produce different diagnostic outcomes, underscoring the importance of using validated, standardized comparison methodology [10]Verified Effects of Two Methods of Comparing Relevant and Control Questions on the Accuracy of Psychophysiological Detection of Deception
Confirms that different methods of comparing relevant and control question responses produce different diagnostic outcomes. Modern scoring systems like the Empirical Scoring System (ESS), developed by Nelson, Handler, and colleagues, provide evidence-based normative scoring methods that increase objectivity and reliability [14]Verified Scientific Basis for Polygraph Testing
Confirms event-specific diagnostic polygraph accuracy of.89 (CI.83 to.95) and screening accuracy of.85 (CI.77 to.93).

It is worth noting that polygraph examinations can also yield inconclusive results — meaning the physiological data does not clearly indicate either truthfulness or deception. The APA meta-analysis reported an estimated inconclusive rate of 11% for event-specific diagnostic testing [2]Verified APA Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms 89% accuracy for event-specific diagnostic polygraph techniques (CI 83-95%), 85% for screening (CI 77-93%), and 87% overall across 38 studies. Research suggests that medications like Xanax do not reliably defeat polygraph testing — see our expert guide on whether Xanax can help beat a polygraph.

Your Rights and What to Expect

If you are scheduled for a polygraph examination, understanding the relevant question process empowers you to ensure you receive a fair and valid test. Here are the key consumer takeaways:

You will see every question before the test begins. APA Standards require that all questions — including relevant questions — be reviewed with you during the pre-test phase [11]Verified APA Standards of Practice
Establishes professional standards for polygraph examination conduct including question formulation requirements and pre-test review procedures. You have the right to ask for clarification or rewording of any question you do not fully understand.

No surprise questions are permitted. If an examiner introduces a question during chart collection that was not reviewed during the pre-test, this violates professional standards and could invalidate the examination.

You should understand every word. If a question contains a term you interpret differently than the examiner intends, speak up during the pre-test. Shared understanding is essential for valid results.

The test should focus on specific behaviors. Questions about what you "think" or "feel" are generally less reliable than questions about what you "did" [1]Verified Question Formulation: Irrelevant, Relevant, and Comparison Questions
Establishes that all polygraph techniques utilize four question categories with principles including yes/no format, single-issue focus, and avoidance of legal terminology. If you notice your questions are vague or emotionally loaded, you can request more specific phrasing.

Two to four relevant questions per chart is standard. If an examiner is asking significantly more relevant questions per chart, this deviates from most validated techniques and could reduce accuracy.

You can verify the examiner's credentials. Professional examiners should be able to tell you which validated technique they are using and confirm that it is approved by the APA. For guidance on evaluating whether you received a fair test, see our article on whether you can beat a polygraph exam.

Evaluating Polygraph Question Quality

For legal professionals and HR managers, the quality of relevant question formulation is often the most productive area to evaluate when reviewing polygraph examination results.

Were the questions behaviorally anchored? Questions targeting specific actions are more diagnostically reliable than questions targeting mental states or knowledge. A well-formulated relevant question describes an observable behavior within a defined timeframe.

Were compound questions avoided? Any relevant question containing "and" or "or" that joins two separate allegations creates diagnostic ambiguity and may be grounds for challenging the examination results.

Was the pre-test review conducted properly? Documentation should show that all questions were reviewed and agreed upon with the examinee before chart collection began. The EPPA specifically requires this for workplace examinations [15]Verified Employee Polygraph Protection Act of 1988
Federal law prohibiting most private employers from using polygraph tests with limited exceptions and strict procedural requirements.

Was a validated technique used? The examination report should identify the specific technique employed and confirm that it is among those validated in the APA's meta-analytic research [2]Verified APA Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms 89% accuracy for event-specific diagnostic polygraph techniques (CI 83-95%), 85% for screening (CI 77-93%), and 87% overall across 38 studies. ASTM E2062 provides the standard guide for PDD examination procedures [16]Verified ASTM E2062 Standard Guide for PDD Examination Standards of Practice
ASTM International technical standard establishing essential elements for polygraph examination procedures under Committee E52, while ASTM E2031 establishes quality control requirements [17]Verified ASTM E2031 Standard Practice for Quality Control of PDD Examinations
Establishes essential and recommended procedures for quality control of polygraph examinations.

Were sufficient chart repetitions collected? Most validated techniques require a minimum of three chart presentations to ensure adequate data for scoring. The number of relevant questions should typically be limited to 2-4 per chart to maintain diagnostic precision.

The Honts et al. (2021) meta-analysis found that level of motivation had a positive linear relationship with accuracy outcomes [7]Verified A Comprehensive Meta-Analysis of the Comparison Question Polygraph Test
The largest meta-analysis of the CQT, analyzing 138 datasets with effect size of 0.69 and AUC of 0.91. Found motivation level has positive linear relationship with accuracy and no publication bias, which means that real-world forensic examinations — where stakes are highest — may actually perform better than laboratory studies suggest. For legal professionals considering using polygraph evidence, understanding the differences between diagnostic and screening polygraphs is essential.