Polygraph Test Formats Explained: Which One Will You Face?

Not All Polygraph Tests Are the Same

The term "lie detector test" is a broad label encompassing multiple distinct testing formats, each engineered with a different scientific rationale, question structure, and scoring methodology. Understanding which format you will face — and why — is one of the most important steps you can take before sitting for any polygraph examination. For a comprehensive overview of polygraph testing in general, see our guide to the purpose and use of the lie detector test in the USA.

The format your examiner uses directly affects what questions you will be asked, how your physiological responses are interpreted, and how accurate the results are likely to be. The American Polygraph Association (APA) maintains a list of validated polygraph techniques that examiners are expected to use [1]Verified Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms 87% overall accuracy (CI 80%–94%), 89% for single-issue diagnostic, 85% for multi-issue screening across 38 studies and 3,723 examinations. Using a non-validated or improperly administered format can compromise results and may render the entire examination scientifically unreliable.

What Do We Mean by 'Format'?

A polygraph test format (also called a "technique" or "protocol") refers to the specific structured arrangement of question types, the sequence in which they are presented, and the rules for how the examiner scores your physiological data. Think of it as the blueprint governing every aspect of the exam — from the pre-test interview through the in-test data collection to the final scoring and opinion.

The APA's 2011 meta-analytic survey reviewed 38 studies encompassing 3,723 examinations and found that validated polygraph techniques produced an overall decision accuracy of 87% (confidence interval 80%–94%) with a 13% inconclusive rate [1]Verified Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms 87% overall accuracy (CI 80%–94%), 89% for single-issue diagnostic, 85% for multi-issue screening across 38 studies and 3,723 examinations. This underscores the importance of using properly validated formats.

A Brief History of Polygraph Format Development

The evolution of polygraph formats mirrors the broader development of the polygraph itself. The earliest technique — the Relevant-Irrelevant Test — emerged in the 1920s from the work of John Larson and was refined by Leonarde Keeler. By the late 1940s, John E. Reid introduced the revolutionary concept of the comparison (control) question in 1947 [2]Verified Air Force Modified General Question Technique (AFMGQT) Documentation
Confirms AFMGQT is a modified version of the Reid technique, adopted by the U.S. Army in 1966 and modified in 1968; widely used across U.S. Federal Government, which became the foundation for virtually all modern specific-issue testing.

In the 1960s, Cleve Backster refined the CQT into the Zone Comparison Test, establishing scoring rules still in use today [2]Verified Air Force Modified General Question Technique (AFMGQT) Documentation
Confirms AFMGQT is a modified version of the Reid technique, adopted by the U.S. Army in 1966 and modified in 1968; widely used across U.S. Federal Government. Meanwhile, David Lykken introduced the Guilty Knowledge Test (GKT) in 1959 [3]Verified The GSR in the Detection of Guilt
Foundational publication where David Lykken introduced the Guilty Knowledge Test in 1959, and researchers in Israel and Japan would develop it further as the Concealed Information Test. In 1970, David Raskin at the University of Utah began a systematic study of the comparison question polygraph technique, leading to the creation of the Utah CQT approach [4]Verified Utah Approach to Comparison Question Polygraph Testing
Confirms David Raskin began studying the CQT at the University of Utah in 1970; documents the Utah-CQT and Utah Numerical Scoring System from 30+ years of research. Over the following decades, directed lie variants, federal standardized protocols, and computerized scoring algorithms such as PolyScore and CPS transformed the field into what it is today [5]Verified Development of a Deep-Learning-Based Computerized Scoring Algorithm
Confirms PolyScore was developed by Johns Hopkins University Applied Physics Laboratory; CPS developed at University of Utah Psychology Laboratory; accuracy rates 85–92% for conventional algorithms.

The Dominant Format in Modern Polygraph Testing

The Comparison Question Test — sometimes still referred to as the Control Question Test — is the single most widely used polygraph format in the world [6]Verified A Comprehensive Meta-Analysis of the Comparison Question Polygraph Test
Confirms CQT reviews generally produce accuracy estimates over 85% from analysis of 138 datasets; no publication bias detected. It forms the backbone of virtually all specific-issue testing conducted by federal agencies, law enforcement, private examiners, and PCSOT programs. If you are taking a polygraph test in North America, the overwhelming probability is that you will face some variant of the CQT.

The CQT was conceived by John E. Reid in 1947 and later refined by Cleve Backster, David Raskin, John Kircher, Charles Honts, and others into the various Zone Comparison formats used today [2]Verified Air Force Modified General Question Technique (AFMGQT) Documentation
Confirms AFMGQT is a modified version of the Reid technique, adopted by the U.S. Army in 1966 and modified in 1968; widely used across U.S. Federal Government[4]Verified Utah Approach to Comparison Question Polygraph Testing
Confirms David Raskin began studying the CQT at the University of Utah in 1970; documents the Utah-CQT and Utah Numerical Scoring System from 30+ years of research. A comprehensive 2021 meta-analysis of 138 CQT datasets confirmed that reviews have "generally produced overall accuracy estimates of over 85%" [6]Verified A Comprehensive Meta-Analysis of the Comparison Question Polygraph Test
Confirms CQT reviews generally produce accuracy estimates over 85% from analysis of 138 datasets; no publication bias detected. The APA's own 2011 meta-analysis found that single-issue diagnostic CQT techniques produced an aggregated decision accuracy of 89% (confidence interval 83%–95%) [1]Verified Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms 87% overall accuracy (CI 80%–94%), 89% for single-issue diagnostic, 85% for multi-issue screening across 38 studies and 3,723 examinations.

Its logic lies in a powerful principle: by comparing your physiological responses to relevant questions (about the issue under investigation) against your responses to comparison questions (broader questions designed to provoke a known level of concern), the examiner can determine whether you are more aroused by the specific allegation or by the general comparison.

How the CQT Works: Question Structure

A typical CQT examination uses four types of questions:

1. Irrelevant Questions: Neutral, factual questions (e.g., "Is today Tuesday?" or "Are you sitting in a chair?") that establish baseline readings and allow the examinee to settle into the testing rhythm. These are not scored.

2. Sacrifice Relevant Questions: A sacrifice relevant question introduces the topic of the examination early in the sequence (e.g., "Do you understand that today's test is about the missing inventory?"). It absorbs the initial orienting response and is not scored.

3. Relevant Questions: These directly address the issue under investigation (e.g., "Did you take any of the missing money from the register?"). A truthful person should show relatively less physiological reactivity to these questions compared to comparison questions. These are scored.

4. Comparison Questions: Deliberately broader questions covering the same general behavioral domain but over a wider time frame (e.g., "Before the age of 30, did you ever take something that didn't belong to you?"). Designed so that a truthful person will be more concerned about them than about the specific relevant questions. They are scored.

For a detailed look at how examiners evaluate these responses, see our guide to spot analysis in polygraph chart marking and scoring.

Key CQT Variants

The CQT is not a single test — it is a family of related formats. The most important variants include:

Backster Zone Comparison Test (ZCT) — Developed by Cleve Backster in the 1960s, featuring a specific "zone" pairing of relevant and comparison questions with strict scoring rules [2]Verified Air Force Modified General Question Technique (AFMGQT) Documentation
Confirms AFMGQT is a modified version of the Reid technique, adopted by the U.S. Army in 1966 and modified in 1968; widely used across U.S. Federal Government. Widely used in private and law enforcement testing.

Utah Zone Comparison Test (UZCT) — Developed by David Raskin and John Kircher at the University of Utah through over 30 years of systematic research [4]Verified Utah Approach to Comparison Question Polygraph Testing
Confirms David Raskin began studying the CQT at the University of Utah in 1970; documents the Utah-CQT and Utah Numerical Scoring System from 30+ years of research. The Utah Numerical Scoring System is considered one of the most reliable and valid methods for scoring specific-incident comparison-question tests [4]Verified Utah Approach to Comparison Question Polygraph Testing
Confirms David Raskin began studying the CQT at the University of Utah in 1970; documents the Utah-CQT and Utah Numerical Scoring System from 30+ years of research. Kircher and Raskin also developed the CPS (Computerized Polygraph System) computerized scoring algorithm at the University of Utah [5]Verified Development of a Deep-Learning-Based Computerized Scoring Algorithm
Confirms PolyScore was developed by Johns Hopkins University Applied Physics Laboratory; CPS developed at University of Utah Psychology Laboratory; accuracy rates 85–92% for conventional algorithms. A separate algorithm, PolyScore, was developed independently at the Johns Hopkins University Applied Physics Laboratory [5]Verified Development of a Deep-Learning-Based Computerized Scoring Algorithm
Confirms PolyScore was developed by Johns Hopkins University Applied Physics Laboratory; CPS developed at University of Utah Psychology Laboratory; accuracy rates 85–92% for conventional algorithms.

Federal Zone Comparison Test (FZCT) — Standardized for use by U.S. federal agencies (FBI, CIA, NSA, etc.) under NCCA protocols. It adapts ZCT principles for both specific-issue and screening applications [7]Verified Federal Psychophysiological Detection of Deception Examiner Handbook
Confirms AFMGQT and ZCT are specific-issue formats; LEPET, R/I Screening Test, and TES are screening formats used in federal government; documents 3-position and 7-position numerical scoring.

Matte Quadri-Track ZCT (MQTZCT) — Developed by James Allan Matte, this variant adds a fourth "track" to address the fear-of-error concern that can affect innocent examinees.

Air Force Modified General Question Test (AFMGQT) — A modified version of the Reid technique, widely used across the U.S. Federal Government for both criminal specific-issue and counterintelligence screening purposes [7]Verified Federal Psychophysiological Detection of Deception Examiner Handbook
Confirms AFMGQT and ZCT are specific-issue formats; LEPET, R/I Screening Test, and TES are screening formats used in federal government; documents 3-position and 7-position numerical scoring[8]Verified AFMGQT Validation Study
Confirms AFMGQT is widely used across U.S. Federal Government for criminal specific and counterintelligence screening purposes. The AFMGQT can accommodate two to four relevant questions and is taught at the National Center for Credibility Assessment (NCCA) [7]Verified Federal Psychophysiological Detection of Deception Examiner Handbook
Confirms AFMGQT and ZCT are specific-issue formats; LEPET, R/I Screening Test, and TES are screening formats used in federal government; documents 3-position and 7-position numerical scoring.

When the CQT Is Used

The CQT (in its various forms) is the default format for criminal investigations (specific-issue diagnostic testing), private lie detector tests (infidelity, theft, false accusations), federal pre-employment screening (FBI, CIA, NSA, CBP, DEA, Secret Service), law enforcement pre-employment testing, PCSOT supervision, and court-ordered or attorney-requested examinations. If someone simply says they are "taking a polygraph test," they are almost certainly referring to a CQT variant.

To learn more about the testing environment, our guide on polygraph examination room setup and APA facility standards covers what to expect. Factors that can affect your results are discussed in 5 things that contaminate polygraph exam results.

Standardizing the Comparison Question

The Directed Lie Test is not a completely separate format — it is a significant modification of the CQT that changes how comparison questions are constructed and administered. In a traditional CQT, comparison questions are "probable lie" questions — the examiner presents them in a way that most people will feel compelled to lie about. The DLT solves a key challenge elegantly: instead of probable lies, the examiner instructs the examinee to lie to a specific question.

For example, the examiner might say: "I'm going to ask you if you have ever told a lie. When I ask that question, I want you to answer 'No,' even though we both know you have." This creates a known, deliberate lie that serves as the comparison baseline. Raskin introduced the Directed Lie Control Question in the 1980s [4]Verified Utah Approach to Comparison Question Polygraph Testing
Confirms David Raskin began studying the CQT at the University of Utah in 1970; documents the Utah-CQT and Utah Numerical Scoring System from 30+ years of research, and it has since become increasingly dominant in federal screening programs.

Advantages of the Directed Lie Approach

Standardization: Every examinee's comparison questions are constructed identically, reducing examiner variability. Transparency: The examinee knows they are lying on the comparison questions. Reduced false positives: Because the comparison stimulus is guaranteed to be a lie, innocent examinees tend to react more consistently to comparison questions. Easier training: New examiners can learn to administer DLT formats more quickly because the comparison question construction is straightforward.

One study of the Directed Lie Screening Test administered by inexperienced examiners to non-naive examinees found an unweighted decision accuracy of.855 with an inconclusive rate of just.086 [9]Verified Criterion Validity of the Directed Lie Screening Test
Confirms DLST achieved.855 unweighted decision accuracy with.086 inconclusive rate when administered by inexperienced examiners, demonstrating the technique's robustness even in less-than-ideal conditions.

Key DLT Formats

Utah DLT: Integrates directed lie comparison questions into the Utah CQT framework. Extensively researched by Raskin and colleagues [4]Verified Utah Approach to Comparison Question Polygraph Testing
Confirms David Raskin began studying the CQT at the University of Utah in 1970; documents the Utah-CQT and Utah Numerical Scoring System from 30+ years of research.

Directed Lie Screening Test (DLST): A screening-specific format based on the technique and procedures for the Test for Espionage and Sabotage (TES). The DLST uses a repeated series of two relevant and two directed-lie comparison questions with the conventional 7-position scoring system [10]Verified Directed Lie Screening Test (DLST) Glossary Entry
Confirms DLST uses repeated series of two relevant and two directed-lie comparison questions with 7-position scoring system. It is validated for screening use according to the APA's meta-analytic review [1]Verified Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms 87% overall accuracy (CI 80%–94%), 89% for single-issue diagnostic, 85% for multi-issue screening across 38 studies and 3,723 examinations.

Federal DLC formats: Several federal agencies have adopted directed lie comparison questions within their standard protocols. The TES itself uses directed lie comparison questions [7]Verified Federal Psychophysiological Detection of Deception Examiner Handbook
Confirms AFMGQT and ZCT are specific-issue formats; LEPET, R/I Screening Test, and TES are screening formats used in federal government; documents 3-position and 7-position numerical scoring.

Despite some debate about whether directed lies are always superior to probable lies, DLT variants are increasingly dominant in federal screening programs and are recommended by many APA-affiliated researchers as the preferred approach for standardized testing.

The Grandfather of All Polygraph Formats

The Relevant-Irrelevant Test is the oldest structured polygraph format, dating back to the 1920s when John Larson and Leonarde Keeler pioneered its use at the Berkeley Police Department. The concept is deceptively simple: the examiner asks questions alternating between relevant questions (about the matter under investigation) and irrelevant questions (completely neutral). If the examinee shows significantly greater physiological arousal to the relevant questions compared to the irrelevant ones, this is interpreted as indicating deception.

Why the RIT Has Largely Been Replaced

The fundamental weakness of the R/I test was identified early: it has no mechanism to account for the natural emotional arousal that even a truthful person feels when asked about the subject of an investigation. If you are truthful but asked "Did you steal the money?" you will likely show more physiological reaction than to "Is today Wednesday?" — not because you are lying, but because the question has personal significance.

This leads to a higher false-positive rate compared to CQT formats. John Reid's introduction of the comparison question in 1947 directly addressed this problem [2]Verified Air Force Modified General Question Technique (AFMGQT) Documentation
Confirms AFMGQT is a modified version of the Reid technique, adopted by the U.S. Army in 1966 and modified in 1968; widely used across U.S. Federal Government. Research has also concluded that the decision accuracy of the R/I screening format is "substantially poorer than other validated screening formats" [1]Verified Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms 87% overall accuracy (CI 80%–94%), 89% for single-issue diagnostic, 85% for multi-issue screening across 38 studies and 3,723 examinations.

While the R/I format is no longer recommended for specific-issue (diagnostic) testing, it still has limited applications in some screening contexts and internationally. For most examinees in North America, the R/I test is primarily of historical interest. External factors that can influence test results are discussed in our guides on alcohol and polygraph testing and caffeine's effects on polygraph tests.

Testing Knowledge, Not Deception

The Concealed Information Test represents a fundamentally different philosophy of polygraph testing. Rather than asking whether someone is lying, the CIT asks: does this person possess knowledge that only someone involved in the event would have?

Developed by David Lykken in 1959 [3]Verified The GSR in the Detection of Guilt
Foundational publication where David Lykken introduced the Guilty Knowledge Test in 1959 and extensively researched by Gershon Ben-Shakhar, Eitan Elaad, and others, the CIT is considered by many academic researchers to have the strongest scientific foundation of any polygraph format [11]Verified The Validity of Psychophysiological Detection of Information with the GKT: A Meta-Analytic Review
Confirms CIT mean effect size of 1.55 across 80 studies; correct detection rates 78–86% for guilty, 94–99% for innocents; effect size of 3.12 under optimal conditions. The P300-based CIT paradigm, established by Farwell and Donchin in 1991, achieved 100% accuracy in determinate cases with no false positives or negatives [12]Verified The Truth Will Out: Interrogative Polygraphy with Event-Related Brain Potentials
Foundational P300-based Guilty Knowledge Test achieved 100% accuracy in determinate cases (87.5% overall) with no false positives or negatives[13]Verified P300-Based Brain-Computer Interface Deception Detection
Demonstrated large effect sizes (d = 1.59–1.89) for P300-based concealed information detection with improved countermeasure resistance.

How the CIT Works

The CIT operates on the principle of the orienting response — when a person encounters a meaningful stimulus they recognize, their autonomic nervous system produces a measurable reaction. The test presents multiple-choice style questions where only one option is the "key" item (known only to someone involved in the event), and the remaining options are plausible but incorrect alternatives.

For example, in a robbery investigation: "The stolen item was... A) a necklace? B) a watch? C) a ring? D) a bracelet? E) earrings?" If the stolen item was a ring and the examinee consistently shows the strongest response to "ring" across multiple question sets, this indicates they possess concealed information.

A landmark meta-analysis by Ben-Shakhar and Elaad (2003) covered 80 laboratory studies with 5,198 participants and reported an overall average effect size (Cohen's d) of 1.55, rising to 3.12 under optimal conditions [11]Verified The Validity of Psychophysiological Detection of Information with the GKT: A Meta-Analytic Review
Confirms CIT mean effect size of 1.55 across 80 studies; correct detection rates 78–86% for guilty, 94–99% for innocents; effect size of 3.12 under optimal conditions. More recent research using P300 brain-wave measures has demonstrated large effect sizes (d = 1.59–1.89) for detection with improved countermeasure resistance [13]Verified P300-Based Brain-Computer Interface Deception Detection
Demonstrated large effect sizes (d = 1.59–1.89) for P300-based concealed information detection with improved countermeasure resistance.

Strengths of the CIT

The CIT offers several notable advantages:

Exceptionally low false-positive rate: A meta-analysis of laboratory CIT studies by Elaad found that the weighted average false-positive rate was just 4.1% [14]Verified Broadening the Use of the Concealed Information Test in the Field
Confirms CIT false-positive rate of 4.1% and false-negative rate of 19.4% from Elaad meta-analysis; CIT accepted as evidence in Japan since Supreme Court 1968 decision; 5,000 CITs annually in Japan. An innocent person who does not know the crime details will respond randomly to all alternatives, and the false-positive rate can be mathematically determined in advance [14]Verified Broadening the Use of the Concealed Information Test in the Field
Confirms CIT false-positive rate of 4.1% and false-negative rate of 19.4% from Elaad meta-analysis; CIT accepted as evidence in Japan since Supreme Court 1968 decision; 5,000 CITs annually in Japan.

Strong theoretical foundation: The orienting response is a well-established phenomenon in psychophysiology with decades of research support [11]Verified The Validity of Psychophysiological Detection of Information with the GKT: A Meta-Analytic Review
Confirms CIT mean effect size of 1.55 across 80 studies; correct detection rates 78–86% for guilty, 94–99% for innocents; effect size of 3.12 under optimal conditions.

Admissibility in Japan: Japan is the only country where the CIT has been widely and systematically used in criminal investigations for over 50 years [14]Verified Broadening the Use of the Concealed Information Test in the Field
Confirms CIT false-positive rate of 4.1% and false-negative rate of 19.4% from Elaad meta-analysis; CIT accepted as evidence in Japan since Supreme Court 1968 decision; 5,000 CITs annually in Japan. About 100 trained examiners perform approximately 5,000 CITs per year [14]Verified Broadening the Use of the Concealed Information Test in the Field
Confirms CIT false-positive rate of 4.1% and false-negative rate of 19.4% from Elaad meta-analysis; CIT accepted as evidence in Japan since Supreme Court 1968 decision; 5,000 CITs annually in Japan. Japan's Supreme Court admitted polygraph results as evidence in 1968, and CIT results have been accepted in court since the 1960s [14]Verified Broadening the Use of the Concealed Information Test in the Field
Confirms CIT false-positive rate of 4.1% and false-negative rate of 19.4% from Elaad meta-analysis; CIT accepted as evidence in Japan since Supreme Court 1968 decision; 5,000 CITs annually in Japan[15]Verified Polygraphic Examinations in Japan: Application of the GKT in Forensic Investigations
Confirms Japanese Supreme Court admitted polygraph evidence in 1968; GKT has been the main method since the 1950s with about 5,000 examinations annually, though the probative value is assessed on a case-by-case basis.

Objectivity: The multiple-choice structure makes scoring more straightforward and less dependent on examiner interpretation. Reviews summarizing GKT laboratory studies found mean correct detection rates between 78% and 86% for guilty subjects, and between 94% and 99% for innocents [11]Verified The Validity of Psychophysiological Detection of Information with the GKT: A Meta-Analytic Review
Confirms CIT mean effect size of 1.55 across 80 studies; correct detection rates 78–86% for guilty, 94–99% for innocents; effect size of 3.12 under optimal conditions.

Limitations of the CIT

The CIT has important constraints: it requires concealed information that investigators possess but that has not been disclosed to the examinee. This severely limits applicability — one FBI review found usable CIT items in only 7–13% of criminal case files [14]Verified Broadening the Use of the Concealed Information Test in the Field
Confirms CIT false-positive rate of 4.1% and false-negative rate of 19.4% from Elaad meta-analysis; CIT accepted as evidence in Japan since Supreme Court 1968 decision; 5,000 CITs annually in Japan. Media contamination poses a risk if crime details have been publicly reported. The CIT also cannot be used for infidelity testing, pre-employment screening, or PCSOT.

Despite these limitations, Japan's decades of successful field application demonstrates that with proper protocols, the CIT is a powerful investigative tool [14]Verified Broadening the Use of the Concealed Information Test in the Field
Confirms CIT false-positive rate of 4.1% and false-negative rate of 19.4% from Elaad meta-analysis; CIT accepted as evidence in Japan since Supreme Court 1968 decision; 5,000 CITs annually in Japan[15]Verified Polygraphic Examinations in Japan: Application of the GKT in Forensic Investigations
Confirms Japanese Supreme Court admitted polygraph evidence in 1968; GKT has been the main method since the 1950s with about 5,000 examinations annually. Emerging technologies like facial expression analysis and thermal imaging are also being explored to supplement traditional polygraph methods [16]Verified Recognition of Emotions by Analysing Facial Expressions with FaceReader vs Detection of Deception by Polygraph Examination
Explored integration of facial expression analysis technology with traditional polygraph examination during concealed information testing[17]Verified Experiments in Using Face Temperature Changes as an Indicator in Instrumental Detection of Deception
Areas near the nose showed full consistency with GSR recordings; demonstrated feasibility of thermal imaging for deception detection.

Broad-Topic Testing for Pre-Employment and Supervision

Screening polygraph formats differ from diagnostic (specific-issue) formats in a critical way: instead of focusing on a single event, they cover multiple broad topic areas simultaneously. These formats are designed for situations where the goal is general suitability assessment rather than resolving a specific factual dispute.

If you are applying for a job with the FBI, CIA, NSA, CBP, DEA, Secret Service, or any federal agency requiring polygraph screening, you will face a screening format. Our guide on what to expect in a pre-employment polygraph provides additional context for how these screenings work in practice.

Common Screening Format Types

LEPET (Law Enforcement Pre-Employment Test): The LEPET is a two-phase polygraph examination that addresses security/counterintelligence issues in phase one and suitability issues for employment in phase two [18]Verified NCCA Law Enforcement Pre-Employment Test (LEPET) Documentation
Confirms LEPET is a two-phase screening format used by FBI, DEA, ATF, Secret Service; addresses security/CI issues and suitability issues. It uses a probable lie comparison question technique with structured testing format and is the standard screening format for federal law enforcement agencies including the FBI, DEA, ATF, and U.S. Secret Service [18]Verified NCCA Law Enforcement Pre-Employment Test (LEPET) Documentation
Confirms LEPET is a two-phase screening format used by FBI, DEA, ATF, Secret Service; addresses security/CI issues and suitability issues[19]Verified Department of Defense LEPET Documentation
Confirms LEPET is a two-phase polygraph examination using probable lie comparison question technique for federal law enforcement pre-employment. CBP used the LEPET as its standard applicant polygraph format until switching to the TES-C in 2018 [20]Verified TES-C Pilot Successful, Implemented as CBP's Primary Testing Format
Confirms CBP switched from LEPET to TES-C format effective May 1, 2018 for all law enforcement applicants.

DLST (Directed Lie Screening Test): The DLST is a screening format based on the TES that uses directed lie comparison questions rather than probable lies. It employs a repeated series of two relevant and two directed-lie comparison questions [10]Verified Directed Lie Screening Test (DLST) Glossary Entry
Confirms DLST uses repeated series of two relevant and two directed-lie comparison questions with 7-position scoring system. Validated through the APA's meta-analytic process [1]Verified Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms 87% overall accuracy (CI 80%–94%), 89% for single-issue diagnostic, 85% for multi-issue screening across 38 studies and 3,723 examinations.

TES (Test for Espionage and Sabotage): A counterintelligence screening format used by intelligence community agencies. It focuses specifically on espionage, sabotage, and unauthorized disclosure of classified information and uses directed lie comparison questions [7]Verified Federal Psychophysiological Detection of Deception Examiner Handbook
Confirms AFMGQT and ZCT are specific-issue formats; LEPET, R/I Screening Test, and TES are screening formats used in federal government; documents 3-position and 7-position numerical scoring. A 1997 DoDPI study compared the CISP and TES question formats and found both achieved significant detection rates [21]Verified A Comparison of PDD Accuracy Rates: CISP vs. TES Question Formats
Compared two screening test formats used in US intelligence community; found both achieved significant detection rates with differences in sensitivity and specificity profiles.

CSP (Counterintelligence Scope Polygraph): Covers counterintelligence issues only and is a narrower alternative to full-scope polygraph examinations.

Key Differences Between Screening and Diagnostic Testing

Topic breadth: Screening covers multiple issue areas; diagnostic focuses on one specific allegation.

Accuracy expectations: The APA's 2011 meta-analysis found that multi-issue screening techniques produced an aggregated decision accuracy of 85% (confidence interval 77%–93%), compared to 89% for single-issue diagnostic testing [1]Verified Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms 87% overall accuracy (CI 80%–94%), 89% for single-issue diagnostic, 85% for multi-issue screening across 38 studies and 3,723 examinations. The NRC 2003 report noted that screening accuracy is generally lower than specific-issue accuracy [22]Verified The Polygraph and Lie Detection
Confirms NRC found specific-incident tests discriminate lying from truth at rates above chance but below perfection; screening accuracy lower; APA reported accuracy range 80–98%.

Purpose: Screening is a risk management tool identifying individuals warranting further investigation. Diagnostic testing aims to resolve a specific factual question.

Question depth: Screening questions are broader ("Have you ever committed a serious crime you were not caught for?") while diagnostic questions are narrow ("Did you take the $5,000 from the safe on January 15th?").

For examiners looking to understand these techniques in more depth, our scientific studies methodology guide and post-test interview techniques guide provide essential professional context.

The Building Blocks of Every Polygraph Format

All polygraph formats are built from combinations of specific question types. Understanding these question types helps you understand why different formats produce different results.

Relevant Questions: Present in every format. These directly address the issue being tested. In CQT formats, these are scored against comparison questions. In the RIT, they are scored against irrelevant questions. In the CIT, the "relevant" item is the key (crime-related) option among alternatives.

Comparison (Control) Questions: The defining feature of CQT-family formats. These are either probable lies (traditional CQT) or directed lies (DLT variants). Their purpose is to provide a psychological baseline against which relevant question reactions are measured.

Irrelevant Questions: Neutral questions present in most formats. They help establish baseline physiological readings and are never scored.

Sacrifice Relevant Questions: Used in CQT formats to absorb the initial orienting response when the topic is first introduced. Not scored.

For a deeper look at how different question types interact, see our guide on whether polygraphs can detect partial lies and omissions. Examinees with specific health concerns should also review our thyroid disorders and polygraph accuracy guide.

Manual and Computerized Scoring Methods

Modern polygraph scoring uses both manual numerical scoring systems and computerized algorithms. The two most common manual approaches are the 3-position scale (-1, 0, +1) and the 7-position scale (-3 to +3) [7]Verified Federal Psychophysiological Detection of Deception Examiner Handbook
Confirms AFMGQT and ZCT are specific-issue formats; LEPET, R/I Screening Test, and TES are screening formats used in federal government; documents 3-position and 7-position numerical scoring.

For CQT formats, the examiner compares physiological responses at relevant questions against adjacent comparison questions and assigns numerical values. Positive scores indicate the comparison question produced a greater response (suggesting truthfulness), while negative scores indicate the relevant question produced a greater response (suggesting deception).

Computerized scoring algorithms have enhanced objectivity. Notable systems include PolyScore, developed by the Johns Hopkins University Applied Physics Laboratory, which uses logistic regression models [5]Verified Development of a Deep-Learning-Based Computerized Scoring Algorithm
Confirms PolyScore was developed by Johns Hopkins University Applied Physics Laboratory; CPS developed at University of Utah Psychology Laboratory; accuracy rates 85–92% for conventional algorithms; CPS (Computerized Polygraph System), developed by Kircher and Raskin at the University of Utah using linear discriminant function analysis [5]Verified Development of a Deep-Learning-Based Computerized Scoring Algorithm
Confirms PolyScore was developed by Johns Hopkins University Applied Physics Laboratory; CPS developed at University of Utah Psychology Laboratory; accuracy rates 85–92% for conventional algorithms; and the Objective Scoring System (OSS-3), a free and open-source algorithm available to all practitioners [5]Verified Development of a Deep-Learning-Based Computerized Scoring Algorithm
Confirms PolyScore was developed by Johns Hopkins University Applied Physics Laboratory; CPS developed at University of Utah Psychology Laboratory; accuracy rates 85–92% for conventional algorithms. These systems have demonstrated accuracy rates between 85–92% under laboratory conditions [5]Verified Development of a Deep-Learning-Based Computerized Scoring Algorithm
Confirms PolyScore was developed by Johns Hopkins University Applied Physics Laboratory; CPS developed at University of Utah Psychology Laboratory; accuracy rates 85–92% for conventional algorithms.

For the CIT, traditional Lykken scoring assigns values based on whether the key item produces the largest physiological response, while more modern statistical methods use integrated d-values and p-values across multiple physiological measures [14]Verified Broadening the Use of the Concealed Information Test in the Field
Confirms CIT false-positive rate of 4.1% and false-negative rate of 19.4% from Elaad meta-analysis; CIT accepted as evidence in Japan since Supreme Court 1968 decision; 5,000 CITs annually in Japan. For more on chart analysis, see our spot analysis and chart scoring guide.

Matching Format to Purpose

The format you face depends on the purpose of your examination:

Federal pre-employment screening (FBI, DEA, ATF, Secret Service): You will likely face a LEPET or TES-variant format [18]Verified NCCA Law Enforcement Pre-Employment Test (LEPET) Documentation
Confirms LEPET is a two-phase screening format used by FBI, DEA, ATF, Secret Service; addresses security/CI issues and suitability issues[19]Verified Department of Defense LEPET Documentation
Confirms LEPET is a two-phase polygraph examination using probable lie comparison question technique for federal law enforcement pre-employment[20]Verified TES-C Pilot Successful, Implemented as CBP's Primary Testing Format
Confirms CBP switched from LEPET to TES-C format effective May 1, 2018 for all law enforcement applicants. CBP now uses the TES-C format for all law enforcement applicants [20]Verified TES-C Pilot Successful, Implemented as CBP's Primary Testing Format
Confirms CBP switched from LEPET to TES-C format effective May 1, 2018 for all law enforcement applicants.

Intelligence community screening (CIA, NSA, DIA): TES or CSP formats are standard, covering counterintelligence issues with directed lie comparison questions [7]Verified Federal Psychophysiological Detection of Deception Examiner Handbook
Confirms AFMGQT and ZCT are specific-issue formats; LEPET, R/I Screening Test, and TES are screening formats used in federal government; documents 3-position and 7-position numerical scoring.

State/local law enforcement hiring: Typically a CQT-based screening format, which may vary by agency.

Private lie detector test (infidelity, theft, false accusations): A CQT variant — most commonly the Utah CQT, Backster ZCT, or a federal-style format adapted for private use. Our guide on private lie detector test confidentiality covers privacy considerations.

Criminal investigation: A specific-issue CQT format (ZCT, FZCT, AFMGQT, or Utah CQT) [7]Verified Federal Psychophysiological Detection of Deception Examiner Handbook
Confirms AFMGQT and ZCT are specific-issue formats; LEPET, R/I Screening Test, and TES are screening formats used in federal government; documents 3-position and 7-position numerical scoring.

PCSOT (sex offender testing): A CQT-based specific-issue format adapted for post-conviction monitoring.

Court-ordered examination: Typically a CQT format, potentially with the CIT as a supplement in cases where crime-scene details can be protected.

You typically cannot choose your format — the examiner selects the validated technique based on the purpose of your exam and agency protocols.

What the Research Shows

The accuracy of polygraph testing has been extensively studied, though debates about methodology continue among researchers.

The American Polygraph Association's 2011 meta-analytic survey — the most comprehensive review of validated polygraph techniques — analyzed 38 studies involving 3,723 examinations and 11,737 scored results [1]Verified Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms 87% overall accuracy (CI 80%–94%), 89% for single-issue diagnostic, 85% for multi-issue screening across 38 studies and 3,723 examinations. Key findings: single-issue diagnostic techniques achieved 89% aggregated decision accuracy (CI: 83%–95%); multi-issue screening techniques achieved 85% (CI: 77%–93%); and combined validated techniques produced 87% accuracy (CI: 80%–94%) [1]Verified Meta-Analytic Survey of Criterion Accuracy of Validated Polygraph Techniques
Confirms 87% overall accuracy (CI 80%–94%), 89% for single-issue diagnostic, 85% for multi-issue screening across 38 studies and 3,723 examinations.

The APA itself notes that research studies published since 1980 have reported average accuracy rates ranging from 80% to 98% [22]Verified The Polygraph and Lie Detection
Confirms NRC found specific-incident tests discriminate lying from truth at rates above chance but below perfection; screening accuracy lower; APA reported accuracy range 80–98%. A 2021 comprehensive meta-analysis of 138 CQT datasets by Honts et al. confirmed that reviews have "generally produced overall accuracy estimates of over 85%" [6]Verified A Comprehensive Meta-Analysis of the Comparison Question Polygraph Test
Confirms CQT reviews generally produce accuracy estimates over 85% from analysis of 138 datasets; no publication bias detected.

It is important to note that the NRC 2003 report concluded that specific-incident polygraph tests "can discriminate lying from truth telling at rates well above chance, though well below perfection" in populations untrained in countermeasures [22]Verified The Polygraph and Lie Detection
Confirms NRC found specific-incident tests discriminate lying from truth at rates above chance but below perfection; screening accuracy lower; APA reported accuracy range 80–98%. The NRC was more cautious about screening applications, noting that "polygraph accuracy for screening purposes is almost certainly lower" [22]Verified The Polygraph and Lie Detection
Confirms NRC found specific-incident tests discriminate lying from truth at rates above chance but below perfection; screening accuracy lower; APA reported accuracy range 80–98%.

A 2025 public perception study by Gordon Barnes found that the average public rating of polygraph accuracy was 71% for detecting deception and 67% for truthfulness, suggesting that public awareness could benefit from better understanding of validated formats and their track record [23]Verified Damned If You Don't: Public Perceptions of Polygraph Testing and Suspect Willingness to Be Tested
Survey of 302 individuals found average public rating of polygraph accuracy was 71% for detecting deception and 67% for truthfulness.

CIT-Specific Accuracy Data

The CIT stands out for its exceptionally low false-positive rates. A meta-analysis of laboratory CIT studies found a weighted average false-positive rate of just 4.1% and a false-negative rate of 19.4% [14]Verified Broadening the Use of the Concealed Information Test in the Field
Confirms CIT false-positive rate of 4.1% and false-negative rate of 19.4% from Elaad meta-analysis; CIT accepted as evidence in Japan since Supreme Court 1968 decision; 5,000 CITs annually in Japan. Reviews summarizing GKT accuracy found mean correct detection rates between 78% and 86% for guilty subjects, and between 94% and 99% for innocents [11]Verified The Validity of Psychophysiological Detection of Information with the GKT: A Meta-Analytic Review
Confirms CIT mean effect size of 1.55 across 80 studies; correct detection rates 78–86% for guilty, 94–99% for innocents; effect size of 3.12 under optimal conditions.

The P300-based CIT paradigm has demonstrated particularly impressive results. Farwell and Donchin's foundational 1991 study achieved 100% accuracy in determinate cases (87.5% overall including indeterminate) [12]Verified The Truth Will Out: Interrogative Polygraphy with Event-Related Brain Potentials
Foundational P300-based Guilty Knowledge Test achieved 100% accuracy in determinate cases (87.5% overall) with no false positives or negatives. Rosenfeld's 2011 Complex Trial Protocol demonstrated large effect sizes (d = 1.59–1.89) with improved countermeasure resistance [13]Verified P300-Based Brain-Computer Interface Deception Detection
Demonstrated large effect sizes (d = 1.59–1.89) for P300-based concealed information detection with improved countermeasure resistance. Research into emerging technologies like facial EMG analysis has achieved 73% accuracy in detecting lies using machine learning [24]Verified Lie to My Face: An Electromyography Approach to the Study of Deceptive Behavior
Machine learning analysis of facial muscle activity achieved 73% accuracy in detecting lies, revealing distinct groups based on cheek muscle activation patterns, while face temperature changes near the nose have shown consistency with traditional GSR recordings [25]Verified Experiments in Using Face Temperature Changes as an Indicator in Instrumental Detection of Deception
Areas near the nose showed full consistency with GSR recordings for thermal deception detection.

Beyond Traditional Polygraph Formats

While the core CQT and CIT formats remain dominant, research continues to develop new approaches to credibility assessment. Recent studies have explored integrating facial expression analysis technology with traditional polygraph examination during concealed information testing [16]Verified Recognition of Emotions by Analysing Facial Expressions with FaceReader vs Detection of Deception by Polygraph Examination
Explored integration of facial expression analysis technology with traditional polygraph examination during concealed information testing. Thermal imaging experiments have demonstrated that areas near the nose show full consistency with GSR recordings, suggesting potential supplementary measurement channels [25]Verified Experiments in Using Face Temperature Changes as an Indicator in Instrumental Detection of Deception
Areas near the nose showed full consistency with GSR recordings for thermal deception detection.

Computerized scoring continues to advance, with deep-learning-based algorithms outperforming conventional systems like PolyScore and OSS-3 in some studies [5]Verified Development of a Deep-Learning-Based Computerized Scoring Algorithm
Confirms PolyScore was developed by Johns Hopkins University Applied Physics Laboratory; CPS developed at University of Utah Psychology Laboratory; accuracy rates 85–92% for conventional algorithms. The development of technologies for credibility assessment, including thermal imaging and computerized scoring methods, represents an active area of research that could supplement traditional polygraph instrumentation [26]Verified Development of Technologies and Test Formats for Credibility Assessment
Presented validation data for novel technological approaches including thermal imaging and computerized scoring methods for polygraph enhancement.

For a broader perspective on how polygraphs appear in popular culture, see our guides on polygraph in video games and how true crime books portray polygraph tests. For real-world applications, see our analysis of polygraph tests in the Nova Scotia missing children case.