{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T19:03:06Z","timestamp":1788894186181,"version":"build-2803163510"},"reference-count":35,"publisher":"Public Library of Science (PLoS)","issue":"4","license":[{"start":{"date-parts":[[2026,4,20]],"date-time":"2026-04-20T00:00:00Z","timestamp":1776643200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004350","name":"Studienstiftung des Deutschen Volkes","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100004350","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:p>Cognitive biases, such as adversarial allegiance, can compromise expert witness evaluations and contribute to wrongful convictions. Therefore, the application of debiasing strategies is essential. The Analysis of Competing Hypotheses (ACH) has been proposed as a potential method to reduce such bias, although empirical support remains limited. The present study investigated the effectiveness of the ACH method in mitigating adversarial allegiance in a sample of mock expert witnesses for credibility assessments. In an online experiment, 159 participants with prior knowledge in credibility assessments reviewed a summary of a child sexual abuse case. Before reviewing the case material, participants were randomly assigned to one of three retaining party conditions: defense, accessory prosecution, or court. Next, half of the participants were instructed to apply the ACH method which includes the systematic comparison of alternative hypotheses within a matrix. Meanwhile the control group was instructed to follow the standard approach in credibility assessments in Germany, which includes the evaluation and falsification of alternative hypotheses, albeit in a less structured way than the ACH method. Outcomes were assessed using credibility ratings and an Evidence Score, the latter reflecting the extent to which participants weighed evidence in favor of their retaining party or evaluated information more evenly. No significant differences emerged in credibility ratings across conditions. However, adversarial allegiance was evident in the Evidence Score: defense-retained participants emphasized evidence undermining the statement\u2019s credibility more than those retained by the accessory prosecution. At the same time, the application of the ACH method did not significantly influence credibility ratings or evidence selection. Overall, these findings suggest that the ACH method may have limited utility as a debiasing strategy in the context of credibility assessments and underscore the challenges of mitigating bias in forensic decision-making.<\/jats:p>","DOI":"10.1371\/journal.pone.0346891","type":"journal-article","created":{"date-parts":[[2026,4,20]],"date-time":"2026-04-20T17:40:27Z","timestamp":1776706827000},"page":"e0346891","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":1,"title":["The analysis of competing hypotheses and expert witness testimony: Counteracting adversarial allegiance in witness credibility assessments?"],"prefix":"10.1371","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0844-2105","authenticated-orcid":true,"given":"Jana","family":"Otzipka","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0070-5396","authenticated-orcid":true,"given":"Renate","family":"Volbert","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2026,4,20]]},"reference":[{"issue":"7","key":"pone.0346891.ref001","doi-asserted-by":"crossref","first-page":"705","DOI":"10.1080\/1068316X.2022.2114476","article-title":"Legal psychologists as experts: Guidelines for minimizing bias","volume":"30","author":"A Vredeveldt","year":"2022","journal-title":"Psychology, Crime & Law"},{"issue":"4","key":"pone.0346891.ref002","first-page":"8","article-title":"Cognitive bias and its impact on expert witnesses and the court","volume":"54","author":"IE Dror","year":"2015","journal-title":"Judges Journal"},{"issue":"12","key":"pone.0346891.ref003","doi-asserted-by":"crossref","first-page":"7998","DOI":"10.1021\/acs.analchem.0c00704","article-title":"Cognitive and human factors in expert decision making: Six fallacies and the eight sources of bias","volume":"92","author":"IE Dror","year":"2020","journal-title":"Anal Chem"},{"issue":"10","key":"pone.0346891.ref004","doi-asserted-by":"crossref","first-page":"1889","DOI":"10.1177\/0956797613481812","article-title":"Are forensic experts biased by the side that retained them?","volume":"24","author":"DC Murrie","year":"2013","journal-title":"Psychol Sci"},{"issue":"1","key":"pone.0346891.ref005","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1146\/annurev-lawsocsci-120814-121714","article-title":"Adversarial allegiance among expert witnesses","volume":"11","author":"DC Murrie","year":"2015","journal-title":"Annu Rev Law Soc Sci"},{"issue":"2","key":"pone.0346891.ref006","first-page":"291","article-title":"The multiple dimensions of tunnel vision in criminal cases","volume":"2006","author":"KA Findley","year":"2006","journal-title":"Wisconsin Law Review"},{"issue":"3","key":"pone.0346891.ref007","doi-asserted-by":"crossref","first-page":"209","DOI":"10.1037\/lhb0000114","article-title":"Static-99R reporting practices in sexually violent predator cases: Does norm selection reflect adversarial allegiance?","volume":"39","author":"CS Chevalier","year":"2015","journal-title":"Law Hum Behav"},{"issue":"2","key":"pone.0346891.ref008","doi-asserted-by":"crossref","first-page":"447","DOI":"10.1037\/pas0000048","article-title":"How reliable are Psychopathy Checklist-Revised scores in Canadian criminal trials? A case law review","volume":"27","author":"JF Edens","year":"2015","journal-title":"Psychol Assess"},{"issue":"2","key":"pone.0346891.ref009","doi-asserted-by":"crossref","first-page":"323","DOI":"10.1348\/135532509X468432","article-title":"Psychopathy, expert testimony, and indeterminate sentences: Exploring the relationship between Psychopathy Checklist\u2010Revised testimony and trial outcome in Canada","volume":"15","author":"CD Lloyd","year":"2010","journal-title":"Leg Criminol Psychol"},{"issue":"2","key":"pone.0346891.ref010","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1037\/lhb0000482","article-title":"A general model of cognitive bias in human judgment and systematic review specific to forensic mental health","volume":"46","author":"TMS Neal","year":"2022","journal-title":"Law Hum Behav"},{"issue":"5","key":"pone.0346891.ref011","doi-asserted-by":"crossref","first-page":"524","DOI":"10.1037\/lhb0000198","article-title":"Adversarial allegiance: The devil is in the evidence details, not just on the witness stand","volume":"40","author":"BD McAuliff","year":"2016","journal-title":"Law Hum Behav"},{"key":"pone.0346891.ref012","article-title":"How can I reduce bias in my work? Discussing debiasing strategies for forensic psychological assessments","author":"VA Oberlader","year":"2025","journal-title":"Prof Psychol Res Pract"},{"issue":"6","key":"pone.0346891.ref013","doi-asserted-by":"crossref","first-page":"1231","DOI":"10.1037\/0022-3514.47.6.1231","article-title":"Considering the opposite: A corrective strategy for social judgment","volume":"47","author":"CG Lord","year":"1984","journal-title":"J Pers Soc Psychol"},{"issue":"3","key":"pone.0346891.ref014","doi-asserted-by":"crossref","first-page":"365","DOI":"10.1080\/13218719.2016.1230924","article-title":"A Case Concerning Children\u2019s False Memories of Abuse: Recommendations regarding expert witness work","volume":"24","author":"H Otgaar","year":"2016","journal-title":"Psychiatr Psychol Law"},{"issue":"4","key":"pone.0346891.ref015","doi-asserted-by":"crossref","first-page":"1132","DOI":"10.1111\/tops.12429","article-title":"A scenario approach to the simonshaven case","volume":"12","author":"PJ van Koppen","year":"2020","journal-title":"Top Cogn Sci"},{"issue":"3","key":"pone.0346891.ref016","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1080\/1068316X.2023.2236274","article-title":"The use of alternative scenarios in assessing the reliability of victims\u2019 statements","volume":"31","author":"N Arbiyah","year":"2023","journal-title":"Psychology, Crime & Law"},{"issue":"3","key":"pone.0346891.ref017","doi-asserted-by":"crossref","first-page":"210","DOI":"10.1027\/2151-2604\/a000416","article-title":"Allegiance bias in statement reliability evaluations is not eliminated by falsification instructions","volume":"228","author":"M Sauerland","year":"2020","journal-title":"Zeitschrift f\u00fcr Psychologie"},{"issue":"2","key":"pone.0346891.ref018","first-page":"46","article-title":"Wissenschaftliche Anforderungen an aussagepsychologische Begutachtungen (Glaubhaftigkeitsgutachten)","volume":"9","author":"BGH","year":"1999","journal-title":"Prax Rechtspsychologie"},{"issue":"3","key":"pone.0346891.ref019","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1027\/1016-9040\/a000200","article-title":"Is this testimony truthful, fabricated, or based on false memory? Credibility assessment 25 years after","volume":"19","author":"R Volbert","year":"2014","journal-title":"Eur Psychol"},{"key":"pone.0346891.ref020","volume-title":"Psychology of Intelligence Analysis","author":"RJ Heuer","year":"1999"},{"key":"pone.0346891.ref021","author":"RJ Heuer","year":"2007"},{"key":"pone.0346891.ref022","author":"RJ Heuer","year":"2005"},{"issue":"2","key":"pone.0346891.ref023","doi-asserted-by":"crossref","first-page":"273","DOI":"10.1080\/02684527.2017.1395948","article-title":"Critical epistemology for analysis of competing hypotheses","volume":"33","author":"N Jones","year":"2018","journal-title":"Intelligence and National Security"},{"issue":"3","key":"pone.0346891.ref024","doi-asserted-by":"crossref","first-page":"337","DOI":"10.1080\/02684527.2017.1400230","article-title":"Restructuring structured analytic techniques in intelligence","volume":"33","author":"W Chang","year":"2018","journal-title":"Intelligence and National Security"},{"issue":"6","key":"pone.0346891.ref025","doi-asserted-by":"crossref","DOI":"10.1002\/acp.3550","article-title":"The analysis of competing hypotheses in intelligence analysis","volume":"33","author":"MK Dhami","year":"2019","journal-title":"Appl Cogn Psychol"},{"key":"pone.0346891.ref026","first-page":"1","article-title":"Critical review of the analysis of competing hypotheses technique: Lessons for the intelligence community","author":"J Wilcox","year":"2024","journal-title":"Intelligence and National Security"},{"issue":"3","key":"pone.0346891.ref027","doi-asserted-by":"crossref","first-page":"584","DOI":"10.1109\/TSMCA.2008.918634","article-title":"Confirmation bias in complex analyses","volume":"38","author":"PE Lehner","year":"2008","journal-title":"IEEE Trans Syst, Man, Cybern A"},{"issue":"6","key":"pone.0346891.ref028","doi-asserted-by":"crossref","first-page":"607","DOI":"10.1017\/S1930297500006628","article-title":"Boosting intelligence analysts\u2019 judgment accuracy: What works, what fails?","volume":"13","author":"DR Mandel","year":"2018","journal-title":"Judgm decis mak"},{"key":"pone.0346891.ref029","volume-title":"Cognitive bias in intelligence analysis: Testing the analysis of competing hypotheses method","author":"M Whitesmith","year":"2020"},{"issue":"5","key":"pone.0346891.ref030","doi-asserted-by":"crossref","first-page":"1040","DOI":"10.1111\/risa.13443","article-title":"Improving probability judgment in intelligence analysis: From structured analysis to statistical aggregation","volume":"40","author":"CW Karvetski","year":"2020","journal-title":"Risk Anal"},{"issue":"1","key":"pone.0346891.ref031","doi-asserted-by":"crossref","first-page":"62","DOI":"10.1002\/acp.3738","article-title":"Test of the Analysis of Competing Hypotheses in legal decision-making","volume":"35","author":"E Maegherman","year":"2021","journal-title":"Appl Cogn Psychol"},{"issue":"5","key":"pone.0346891.ref032","doi-asserted-by":"crossref","DOI":"10.1002\/acp.70115","article-title":"The analysis of competing hypotheses in legal proceedings","volume":"39","author":"J Otzipka","year":"2025","journal-title":"Appl Cogn Psychol"},{"issue":"6","key":"pone.0346891.ref033","doi-asserted-by":"crossref","first-page":"939","DOI":"10.1017\/S1930297500008159","article-title":"Coherence of probability judgments from uncertain evidence: Does ACH help?","volume":"15","author":"CW Karvetski","year":"2020","journal-title":"Judgm decis mak"},{"issue":"4","key":"pone.0346891.ref034","doi-asserted-by":"crossref","first-page":"1149","DOI":"10.3758\/BRM.41.4.1149","article-title":"Statistical power analyses using G*Power 3.1: Tests for correlation and regression analyses","volume":"41","author":"F Faul","year":"2009","journal-title":"Behav Res Methods"},{"key":"pone.0346891.ref035","author":"MJ Mierzejewski","year":"2022"}],"container-title":["PLOS One"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0346891","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,20]],"date-time":"2026-04-20T17:40:33Z","timestamp":1776706833000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0346891"}},"subtitle":[],"editor":[{"given":"Max M.","family":"Houck","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2026,4,20]]},"references-count":35,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2026,4,20]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0346891","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,20]]}}}