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Researcher file
Donald J. Krapohl
Development of empirically-based polygraph scoring algorithms and evidence-based testing methodologies
41Studies
2000–2024Active period
23Co-authors
9Research areas
10Journals
Researcher record
NameDonald J. Krapohl
AffiliationNational Center for Credibility Assessment (retired) — United States
Publications41 peer-reviewed studies in this database
Active period2000–2024
Research focusDevelopment of empirically-based polygraph scoring algorithms and evidence-based testing methodologies
About Donald J. Krapohl
Donald J. Krapohl began his polygraph career in the private sector in 1979, conducting testing for attorneys, police departments and commercial firms in St. Louis, Missouri, before being recruited by the US government in 1985 to perform polygraph testing for intelligence and security purposes. His work ultimately led to his assignment in 1997 to the US government's polygraph education and research organization at Fort Jackson, South Carolina (the Defense Polygraph Institute, later the National Center for Credibility Assessment), where he spent six years in the Research Branch before becoming the facility's Deputy Director. He retired from government service in 2015.
Krapohl focused as a researcher on the development of best practices and the use of empirically based methodologies. His work led to, among other advances, a polygraph algorithm now used on most computer polygraphs. He is best known for developing the Objective Scoring System (OSS) and Empirical Scoring System (ESS), computerized algorithms for analyzing polygraph data. His expansive terminology reference for polygraphy is the standard in the field. He was a member of the team that validated the Preliminary Credibility Assessment Screening System, a technology now a major component of force protection for the US military. In his career he has authored more than 100 published research papers, general interest pieces, technical articles and book chapters on credibility assessment and related areas.
Krapohl served as Editor-in-Chief for the publications of the American Polygraph Association (APA) from 1997-2003 and 2007-2014, and as APA President in 2006. He has been the recipient of numerous awards for his research and presentations. He received the John E. Reid Award (the APA's premier research honor) in both 2000 and 2006, and the Leonarde Keeler Award for distinguished service in 2015. Krapohl helped craft the charge given the National Research Council during its survey of the literature on the validity of polygraph screening in 2003. He made technical presentations on the government's use of credibility assessment technologies to workshops hosted by the National Academy of Sciences and the National Science Foundation. He has collaborated extensively with leading polygraph researchers including Mark Handler, Raymond Nelson, Stuart Senter, and Donnie Dutton.
Research methodology profile
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Researchers who have co-authored studies with Donald J. Krapohl.
Publications [41]
All peer-reviewed studies by Donald J. Krapohl in our database.
[001]
2024 • COMPUTER SCORING FIELD Polygraph
Comparison of OSS-3 and PolyScore in Multi-Issue and Single-Issue Field Exams
Compared computerized scoring algorithms on field data. OSS-3 correctly identified 71% truthful and 96% deceptive with 14% inconclusive rate, outperforming PolyScore on multiple-issue tests. [002] 2024 bioRxiv (preprint)Evaluating Physiological Indicators in Detecting Deception with an Automated Interviewing System
The study represents one of the few systematic comparisons of multiple physiological modalities within a single experimental framework, conducted with a diverse Asian population to address generalizability limitations of Western-focused… [003] 2023 European PolygraphTerminology Reference for the Science of Psychophysiological Detection
The reference standardizes terminology across the polygraph profession, providing authoritative definitions grounded in peer-reviewed literature with 94 scientific references, facilitating communication between practitioners, researchers, and the broader scientific community. [004] 2020 Polygraph & Forensic Credibility Assessment: A Journal of Science and Field PracticeElectrodermal Responses: When is Bigger Really Better?
Performance peaked when electrodermal response amplitudes differed by 10-20%, with a subsequent laboratory analysis finding optimal correlation at 30% minimum difference when scoring against the stronger of two comparison questions. [005] 2020 European PolygraphFive Milestones in the History of the Polygraph
Five specific transformative events are identified as having the most profound and lasting impact on polygraph professional practice, representing critical junctures where the field's development fundamentally changed direction. [006] 2020 European PolygraphElectrodermal Response Ratios: Scoring Against the Stronger of Two Comparison Questions in Search of an Optimal Minimum Threshold
The optimal minimum difference for scoring electrodermal responses against the stronger of two comparison questions was 30%, with a point-biserial correlation of 0.680 between scores and ground truth. This threshold… [007] 2018 Polygraph & Forensic Credibility AssessmentReducing Bias in Polygraph Scoring: The Effect of Biasing Information on Blind Evaluation of Polygraph Charts
Polygraph scores and decisions were significantly shifted in the direction of biasing information, with examiners told cases were deceptive scoring more deceptively than those told cases were truthful. [008] 2018 Polygraph & Forensic Credibility Assessment: A Journal of Science and Field PracticeThe difference between the manual and automatic settings for the electrodermal channel and a potential effect on manual scoring
Manual and automatic EDA modes produce substantially similar aggregate outcomes but may diverge in individual scoring decisions, with automatic mode retaining approximately 90% of data while attenuating some complex reaction… [009] 2015 Fundamentals of Polygraph PracticeTest question construction
The chapter establishes standardized construction rules for six question types, emphasizing that proper question formulation is critical to valid results. Key principles include single-issue focus, yes/no format, clear non-accusatory language,… [010] 2015 Fundamentals of Polygraph PracticeAdvanced topics
This is a textbook chapter synthesizing existing knowledge on advanced polygraph practice topics, not original research with statistical findings. [011] 2015 Fundamentals of Polygraph PracticeAlternate technologies
[012] 2015 European PolygraphDecision Accuracy for the Relevant-Irrelevant Screening Test: Influence of an Algorithm on Human Decision-Making
The study addressed the poor interrater reliability problem that has plagued RI screening tests, investigating whether algorithmic support could resolve fundamental reliability issues that undermine the technique's validity. [013] 2015 Fundamentals of Polygraph PracticeScientific issues
[014] 2015 Fundamentals of Polygraph PracticeSpecific-issue testing techniques
The chapter describes three validated comparison question techniques for criminal investigation, with event-specific testing demonstrating aggregated accuracy rates near 89-90% and inconclusive rates around 10-11% when evidence-based protocols are properly… [015] 2014 PolygraphRelevant-Irrelevant Screening Format Accuracy
Concluded that the decision accuracy of the RIR screening format is substantially poorer than other validated screening formats. Provided evidence-based justification for agencies to adopt superior testing methods. [016] 2014 European PolygraphLetter to the Editor: Calculating Polygraph Decision Accuracy
Specific findings cannot be determined without access to the full text of this brief editorial communication. [017] 2013 PolygraphPolygraph Principles: A Literature Review
Comprehensive review of the scientific principles underlying modern polygraph testing, including signal detection theory, test data analysis methods, and statistical foundations. Served as a reference guide for the field. [018] 2011 PolygraphCriterion Validity of the Empirical Scoring System with experienced examiners: Comparison with the seven-position evidentiary model Using the Federal Zone Comparison Technique
No statistically significant differences were found between the ESS and seven-position evidentiary model across 13 dimensions of criterion accuracy when scored by experienced examiners. More than 50 percent of subtotal… [019] 2010 PolygraphA Proposal for Reconciling Theory and Terminology in Polygraph Testing
Addressed the need for standardized terminology and theoretical consistency across polygraph testing methods. Proposed a unified framework to reconcile competing theoretical models and improve scientific communication. [020] 2010 PolygraphAn Assessment of the Backster Either-Or Rule in Polygraph 240 Scoring
Application of the Either-Or Rule increased correct decisions from 70% to 80% and reduced inconclusives from 27% to 17%, with all improvements attributable to better detection of deceptive cases. Backster… [021] 2010 • SHORT REPORT PolygraphA Test of the ESS with Two-Question Field Cases
Validated ESS for two-question test formats. Found accuracy remained robust even with reduced question count, supporting ESS utility for shorter examinations. [022] 2008 European PolygraphTest Structure and Administration
The Utah-CQT approach provides some of the highest rates of criterion accuracy and interrater reliability of any polygraph examination protocol when applied in event-specific testing situations. [023] 2008 PolygraphNelson, Krapohl and Handler 2008
[024] 2008 PolygraphBrute-force comparison: A Monte Carlo study of the Objective Scoring System version 3 (OSS-3) and human polygraph scorers
OSS-3 exceeded the decision accuracy of 10 human scorers and 9 out of 10 individual scorers across six accuracy dimensions. The algorithm demonstrated perfect reliability compared to human interrater reliability… [025] 2008 • USAF STUDY PolygraphEffectiveness of the Air Force Modified General Question Test Format
Validated the USAF-MGQT format with total accuracy of 83.8% and definitive accuracy of 84.9%. Demonstrated effectiveness of the military’s standard examination format. [026] 2008 PolygraphDevelopment and validation of the Objective Scoring System version 3
OSS-3 achieved 88% average decision accuracy with balanced sensitivity and specificity, with computer algorithms providing perfect interrater reliability compared to human scorers (κ = .58–.61) and reduced inconclusive results. [027] 2008 • OSS-3 DEVELOPMENT PolygraphObjective Scoring System, Version 3 (OSS-3): Development and Validation
Described the OSS-3 algorithm and used brute-force methods to compare accuracy against previous versions and human examiners. OSS-3 demonstrated balanced sensitivity/specificity and outperformed 10 human scorers. [028] 2008 • ESS DEVELOPMENT PolygraphAn Empirically Based Normative System for Test Data Analysis
Introduced the Empirical Scoring System based on normative physiological data. Provided validation across 732 confirmed examinations scored by 140 examiners in 16 cohorts. [029] 2008 • MEIRON ASSESSMENT PolygraphAn Assessment of the Backster ‘Either-Or’ Rule in Polygraph Scoring
Empirically tested Backster’s long-standing “Either-Or” scoring rule. Found the rule did not improve accuracy and recommended against its routine use, updating decades of practice. [030] 2008 PolygraphAir Force Modified General Question Test Validation Study
The AFMGQT produced total and definitive accuracy rates that significantly exceeded chance levels for both truthful and deceptive participants in controlled laboratory conditions, providing empirical support for its operational use… [031] 2007 – 2011 PolygraphDevelopment of the Objective Scoring System (OSS) and Empirical Scoring System (ESS)
Developed and validated the OSS and ESS computerized scoring methods, resulting in more objective and stable analysis of psychophysiological outcomes. These systems replaced subjective hand-scoring and significantly improved inter-scorer reliability… [032] 2006 PolygraphNew ratios for scoring electrodermal responses
[033] 2006 PolygraphValidated polygraph techniques
The paper identified which polygraph techniques met validation standards circa 2006, but sparked controversy by including techniques with low accuracy for truthful examinees while excluding others with substantial validity evidence,… [034] 2006 DoDPI Research ReportsValidation Studies for the Preliminary Credibility Assessment Screening System (PCASS)
The research provided initial empirical validation of PCASS as a portable credibility assessment tool designed for minimal training requirements and field deployment in military contexts. [035] 2005 • EVIDENTIARY RULES PolygraphPolygraph Decision Rules for Evidentiary and Paired Testing (Marin Protocol)
Established decision rules specifically for evidentiary-quality polygraph examinations, with more conservative cutscores to minimize errors in legal contexts. [036] 2004 Journal of Applied PsychologyA comparison of polygraph data obtained from individuals involved in mock crimes and actual criminal investigations
While laboratory and field examinees exhibited salient differences in electrodermal, cardiovascular, and respiratory response magnitudes, logistic regression classification accuracy did not significantly differ between settings, supporting the generalizability of laboratory… [037] 2004 PolygraphA Comparison of Polygraph Data Evaluation Conventions Used at the University of Utah and the Department of Defense Polygraph Institute
All scorers achieved highest accuracy using University of Utah chart evaluation rules regardless of training institution, demonstrating that scoring conventions rather than examiner skill accounted for historical accuracy differences between… [038] 2002 Handbook of Polygraph TestingThe polygraph in personnel screening
Personnel screening polygraph demonstrated lower accuracy than specific-incident testing, with innocent examinee identification rates ranging from 88.9% to 98.3% across different formats, indicating false accusation rates of 1.7% to 11.1%… [039] 2000 Journal of Forensic SciencesComparison of computerized polygraph scoring algorithms
All five algorithms demonstrated comparable accuracy (88-91% correct decisions excluding inconclusives) but exhibited false positive rates of 31-46% when inconclusives were treated as errors, with systematic misclassification of innocent subjects… [040] 2000 PolygraphThe frequency of appearance of evaluative criteria in field polygraph charts
Electrodermal activity accounted for 55% of all reactions, followed by cardiograph (26%) and pneumograph (19%). Criteria frequency ranged from 5 to 4,793 appearances, with rank order remaining constant across questions,… [041] 2000 PolygraphAn exploratory study of traditional and objective scoring systems with MGQT field cases
Human scorers demonstrated better sensitivity to deception while the OSS model outperformed human scorers in specificity to truthfulness, revealing that applying cumulative scoring models to spot scoring conditions produced results…Explore all research.
Browse our complete database of 3493 peer-reviewed polygraph studies.