A/HRC/42/CRP.1 required visas.2 The Group’s repeated requests for meetings with officials of the Government of Yemen, the Kingdom of Saudi Arabia, and the United Arab Emirates since September 2018 had remained unanswered at the time of writing. II. Methodology 13. The Group of Experts followed the well-established best practices and methodologies for human rights fact-finding,3 ensuring that the principles of “do no harm”, independence, impartiality, objectivity, transparency, and integrity were strictly adhered to at all stages of its work. A. Standard of proof 14. Consistent with established practices of United Nations fact-finding bodies, the Group of Experts considered whether it had “reasonable grounds to believe” that individual incidents and patterns of conduct had occurred. The Group of Experts relied on this determination as the standard of proof for its factual findings, which underpinned determinations of whether such incidents and patterns of conduct amounted to violations of international human rights law, international humanitarian law, and, where relevant, to international crimes. 15. The Group of Experts has in this report referred to instances where it found reasonable grounds to believe that a competent authority should further investigate incidents or patterns of conduct. Such findings are based upon the Group having obtained a reliable body of information, consistent with other material, upon which a reasonable and ordinarily prudent person would believe that the incident or pattern of conduct has occurred. The “reasonable grounds to believe” standard of proof is lower than the standard normally required in criminal proceedings to achieve a conviction. However, it is considered sufficient to call for further investigations by a competent authority, and the Group of Experts applied it as such. 16. In reaching factual findings based on its investigations, the Group of Experts followed the established methodology for this standard of proof of requiring at least one credible direct source of information, independently corroborated by at least one or more additional credible sources of information. 17. The Group of Experts considered the following to be sources of direct information: interviews with victims; interviews with direct eyewitnesses to an event; videos, photographs, satellite imagery and documents whose authenticity has been assured; decrees, regulations and directives issued by governments; publicly available statements from parties to the conflict, including statements made via State media outlets; statistics, surveys, reports, and other quantitative and qualitative information generated by United Nations organisations, bodies, agencies, funds and programmes. 18. The Group of Experts considered the following for the purposes of corroborating information from direct sources, and for providing a contextual understanding: information, including witness testimony, situational analysis, descriptions of patterns of conduct and other material from publications or submissions by the United Nations, governments, human rights and humanitarian organisations; affidavits or other authenticated witness Following its previous practice, in the present report the Group of Expert uses the term “de facto authorities” to refer to the authorities based in Sana’a, where Ansar Allah as a political movement is the main actor (supported by former President Saleh until his killing in December 2017). The de facto authorities are supported by an armed group, referred to as the “Houthis”, which includes affiliated Popular Committees. Prior to the death of President Saleh, these armed groups were referred to as “Houthi-Saleh” fighters. 3 See United Nations Office of the High Commissioner for Human Rights (“OHCHR”), International Commissions of Inquiry and Fact-Finding Missions on International Human Rights Law and International Humanitarian Law - Guidance and Practice, 2015. 2 7