1. Statement of Purpose
1.1 The purpose of these Standards is to promote the highest degree of decision accuracy in credibility assessment by members of the Society. All examinations conducted by BPS members shall be carried out in compliance with applicable UK law and with these Standards.
2. Definitions
2.1 Polygraph examination — a psychophysiological test of deception or recognition (sometimes referred to colloquially as a “lie detector” test). The examination comprises an interview phase, a data acquisition phase during which physiological responses are permanently recorded, and an analysis phase during which the recorded data are numerically quantified to produce a categorical test result. The psychological basis of responses is understood to involve attention, cognition, emotion, and behavioural conditions.
2.2 Evidentiary Examination — an examination in which the written and stated purpose agreed by the parties is to provide a diagnostic opinion as evidence in a pending judicial proceeding.
2.3 Paired Testing Examination — examinations conducted in tandem on two or more individuals by different examiners who are mutually blind to the other test result, regarding a single central contested fact. Paired testing is used by voluntary stipulation between the parties to resolve disputed facts.
2.4 Investigative Examination — an examination intended to supplement or assist an investigation and for which the examiner has not been informed, and does not reasonably believe, that the result will be tendered as evidence in a court proceeding. Investigative examinations may be conducted for screening or to investigate known allegations or incidents.
2.5 Diagnostic Examination — an event-specific evidentiary or investigative examination to assist in determining the veracity of an examinee regarding their knowledge of or involvement in a reported issue or allegation.
2.6 Screening Examination — an examination conducted in the absence of a reported incident or allegation. Screening examinations may be single-issue or multiple-issue.
2.7 Test Data Analysis — any structured method, whether manual or automated, for the evaluation and interpretation of recorded physiological data in terms of probabilistic margins of uncertainty or categorical test decisions concerning the examinee’s truthfulness or concealed knowledge.
2.7.1 Diagnostic Opinion — a professional opinion based on a polygraph technique that meets the criterion validity requirements for evidentiary or paired testing. Results are reported using the terms Deception Indicated (DI), No Deception Indicated (NDI), Inconclusive (INC), or No Opinion (NO) for deception tests, and Recognition Indicated (RI), No Recognition Indicated (NRI), or No Opinion (NO) for recognition tests.
2.7.2 Screening Opinion — a professional opinion based on a polygraph technique that meets the requirements for screening purposes. Results are reported using the terms Significant Response (SR), No Significant Response (NSR), Inconclusive (INC), or No Opinion (NO).
2.8 Polygraph Technique — a combination of: (a) a testing format with a published description of administration procedures conforming to evidence-based principles for target selection, question construction, and administration; and (b) a published description of the test data analysis model, including physiological features, transformations, decision rules, and normative data.
2.8.1 Techniques for evidentiary examinations shall be those for which there exist at least two published empirical studies (original and replicated) demonstrating an unweighted average accuracy rate of 90% or greater, excluding inconclusive results, which shall not exceed 20%.
2.8.2 Techniques for paired testing shall be those for which there exist at least two published empirical studies (original and replicated) demonstrating an unweighted average accuracy rate of 86% or greater, excluding inconclusive results, which shall not exceed 20%.
2.8.3 Techniques for investigative testing shall be those for which there exist at least two published empirical studies (original and replicated) demonstrating an unweighted average accuracy rate of 80% or greater, excluding inconclusive results, which shall not exceed 20%.
2.8.4 Techniques used for screening purposes shall be those for which there exist at least two published empirical studies (original and replicated) demonstrating an unweighted accuracy rate significantly greater than chance, and shall be used in a successive-hurdles approach which entails additional testing with validated methods when the screening test is not favourably resolved.
2.9 PCSOT Examiner — a Sex Offender Testing">Post-Conviction Sex Offender Testing examiner: a member who conducts examinations of persons managed as sex offenders as a condition of treatment, probation, licence, or supervised release, and who has completed specialised training consistent with APA PCSOT standards.
3. Examiner Responsibilities
3.1 Every practising member shall complete a minimum of 30 hours of continuing professional development every two years in coursework related to polygraphy, in accordance with the Society’s CPD and Accreditation Policy. Members are responsible for maintaining their own records to evidence compliance.
3.2 Members shall accurately represent their BPS membership category, their APA membership category, their academic credentials, and any licensure or certification status.
3.3 Before conducting an examination, the member shall make reasonable efforts to determine that the examinee is a suitable candidate for polygraph testing. Basic inquiries into the medical and psychological condition of the examinee shall be made where permitted by law. Observable or reasonably known mental, physical, or medical conditions shall be considered when conducting and evaluating an examination, and where necessary the member shall decline to proceed.
4. Instrumentation and Recording
4.1 Examinations shall be conducted with properly functioning instrumentation that records, at a minimum:
- respiration patterns, using two pneumograph components to record thoracic and abdominal patterns separately;
- electrodermal activity reflecting relative changes in the conductance or resistance of the epidermal tissue;
- cardiovascular activity, including changes in relative blood pressure, pulse rate, and Amplitude">pulse amplitude; and
- a seat activity sensor.
4.2 Other physiological data may be recorded during testing but shall not be used to formulate probabilistic or categorical conclusions unless validity is supported by replicated and published research.
4.3 Physiological recordings during each test shall be continuous and of sufficient amplitude to be readable by the examiner and by any reviewing examiner.
5. Test Location and Conditions
5.1 The testing environment shall be reasonably free from distractions, reasonably private, and suitable for the purposes of the examination.
5.2 A member conducting an examination in circumstances that are or may be subject to public viewing (including any form of broadcast or recording for public release) shall not render any opinion regarding the truthfulness of the examinee on the basis of that examination. Reenactments shall be clearly conveyed as such to viewers; where the member determines that this has not been done, the member shall immediately notify the Management Committee.
6. Preparation
6.1 Prior to an examination, the member shall dedicate sufficient time to identify and discuss the examination issues and any potential problem areas.
7. Pretest Practices
7.1 The member shall obtain information sufficient to identify the examinee.
7.2 The member shall obtain the informed written consent of the examinee before testing. Informed consent shall follow an overview of the polygraph process, including the instrumentation and sensors used, the fact of any audio or video recording, the issues to be discussed, requirements for cooperation, and the persons or bodies to whom information and results will be reported.
7.3 The member shall review all test questions with the examinee before recording physiological responses.
7.4 The member shall conduct the examination in a neutral manner and shall not display or express any bias regarding the truthfulness of the examinee before completion of testing.
8. Testing
8.1 A member shall use evidence-based validated testing techniques. A technique is considered valid for the purposes of these Standards if supported by research conducted in accordance with the APA’s research standards. Where an examination deviates from the protocols of a validated technique, the deviation shall be explained in writing in the examination file.
8.2 Nothing in these Standards prevents members or researchers from investigating and developing improved methods. Techniques that do not meet these Standards for validation are experimental methods.
8.3 A member employing an experimental technique in the field shall comply with applicable law relating to human-subject research, shall inform the examinee and the retaining party of the use of the experimental technique, and shall not use the experimental result in isolation to render a diagnostic or screening decision.
8.4 Nothing in these Standards prohibits the use of other supportive methodologies that do not meet the requirements of these Standards (for example, Yes Test or Searching Peak of Tension). Non-validated techniques shall not, however, be used in isolation to render a screening or diagnostic decision.
8.5 An audio or audio-video recording of all phases of the examination shall be maintained as part of the examination file, for a minimum of one year or as otherwise required by applicable law or the instructions of the retaining party.
8.6 Members shall conduct an acquaintance test for all diagnostic, evidentiary, paired-testing, initial screening, and initial investigative examinations.
8.7 Questions used in the assessment of truth and deception shall be followed by time intervals of not less than 20 seconds from question onset to question onset.
8.8 Members shall use standardised chart markings">chart markings.
8.9 All phases of the examination (pre-test interview, in-test, and post-test interview where conducted) shall be conducted in person by the member. Electronic communications shall not be substituted for in-person communication.
8.10 Examinations shall be scheduled for not less than 90 minutes. A member shall not conduct more than five examinations of any type in one day.
8.11 Members who test persons managed as sex offenders as a condition of treatment, probation, licence, or supervised release shall have earned a certificate of training for a minimum of 40 hours of specialised PCSOT instruction consistent with APA standards.
8.12 Members who conduct examinations under the statutory polygraph testing regime administered by HMPPS (under the Offender Management Act 2007 or the Domestic Abuse Act 2021) shall additionally comply with all directions, policies, and contractual obligations imposed by HMPPS.
9. Protection and Retention of Records
9.1 Members shall ensure that all polygraph reports, data, recordings, information, and documents are protected against loss, inappropriate release, unauthorised access, alteration, and misuse, consistent with the UK GDPR, the Data Protection Act 2018, and the Society’s Privacy and Confidentiality Policy.
9.2 Reports and related work product shall be released only to the authorised persons identified in the signed informed consent, to persons named in a court order, or as otherwise required by law.
9.3 Unless required by law, members shall not release polygraph reports, test questions, data, recordings, information, or documents to persons who may use that material to neutralise or interfere with the effectiveness of future examinations.
9.4 Examination records shall be retained for a minimum of three years, or as otherwise required by law, contract, or court order.
10. Data Analysis and Test Results
10.1 Members shall render a conclusion for each examination based on a method of data analysis validated consistently with paragraph 2.8 of these Standards.
10.2 A member may suspend judgment and issue a result of Inconclusive or No Opinion where there is countervailing information or an identified external factor that reduces confidence in the decision that would otherwise be based on the polygraph data.
10.3 Members shall document in the examination report and working notes sufficient information and analysis parameters to support replication of the analysis and conclusion by a reviewing examiner.
10.4 For evidentiary examinations, the member shall report the probabilistic results for the technique and/or the rendered opinion.
10.5 A test result shall not be final until documented in the examination report and issued to the retaining party. Where no written report is requested, the member shall retain sufficient notes and materials to permit a complete written report to be produced subsequently.
10.6 Members shall maintain confidentiality of their work until a release is obtained from the examinee. Information shall be released only to the person or body identified in the signed release.
11. Quality Control Review
11.1 A member who is subject to quality control review under the Society’s procedures or a retaining party’s instructions shall provide, at a minimum:
- the digital or electronic polygraph data in original form;
- all test questions;
- referral information sufficient to review target selection and question formulation;
- an audio-video or audio recording of the examination in its entirety;
- the examination report; and
- any additional information necessary to replicate the analysis and result.
11.2 Privileged communications and genuine work product may be excluded from disclosure for quality control purposes.
12. Compliance
12.1 Breach of these Standards is a disciplinary matter under the Complaints, Discipline and Appeals Procedure.
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This document is published by the British Polygraph Society, a professional body for polygraph examiners constituted by its members in 2017 and governed by a written Constitution under the law of England and Wales. For corrections or queries, contact the Secretary at the address above.
© 2026 British Polygraph Society. All rights reserved. This is a governing document of the Society. It may be quoted briefly for commentary, reporting, or study in accordance with fair-dealing exceptions under the Copyright, Designs and Patents Act 1988. It may not be reproduced in full, adapted, or redistributed — whether online or in print — without the Society's prior written permission. Requests for permission should be addressed to the Secretary at the correspondence address above.