In January 2019, a survey conducted by Opinion Matters, on behalf of the Holocaust Memorial Day Trust found that 5% of UK adults did not believe the Holocaust took place and one in 12 (8%) believed its scale has been exaggerated. One in five respondents incorrectly answered that less than 2 million Jews were murdered, and 45% couldn't say how many people were murdered in the Holocaust. Speaking in light of the survey's findings, Karen Pollock, chief executive of the Holocaust Educational Trust, said: "One person questioning the truth of the Holocaust is one too many, and so it is up to us to redouble our efforts to ensure future generations know that it did happen and become witnesses to one of the darkest episodes in our history." The BBC Radio 4 More or Less programme, specialising on statistics, investigated the survey finding it was unlikely to be accurate. Participants were incentivised to complete the online survey by shopping vouchers encouraging speedy answering, and the principal question was a "reverse question" with most participants having to give the reverse answer to surrounding questions requiring careful answering. Another question asked how many Jewish people had been murdered in the holocaust with only 0.2% of participants giving the answer zero, which was considered to be a closer estimate of the number of UK adults that did not believe the Holocaust took place.