Reply to Response to Vacuous standards – subversion of the OSAC standards-development process

This Letter to the Editor is a reply to Mohammed et al. (2021) https://doi.org/10.1016/j.fsisyn.2021.100145, which in turn is a response to Morrison et al. (2020) “Vacuous standards – subversion of the OSAC standards-development process” https://doi.org/10.1016/j.fsisyn.2020.06.005

A comment on the PCAST report:skip the “match”/“non-match” stage

This letter comments on the report “Forensic science in criminal courts: Ensuring scientific validity of feature-comparison methods” recently released by the President's Council of Advisors on Science and Technology (PCAST). The report advocates a procedure for evaluation of forensic evidence that is a two-stage procedure in which the first stage is “match”/“non-match” and the second stage is empirical assessment of sensitivity (correct acceptance) and false alarm (false acceptance) rates. Almost always, quantitative data from feature-comparison methods are continuously-valued and have within-source variability. We explain why a two-stage procedure is not appropriate for this type of data, and recommend use of statistical procedures which are appropriate

Reply to Response to Vacuous standards – Subversion of the OSAC standards-development process

This Letter to the Editor is a reply to Mohammed et al. (2021) https://doi.org/10.1016/j.fsisyn.2021.100145, which in turn is a response to Morrison et al. (2020) “Vacuous standards – subversion of the OSAC standards-development process” https://doi.org/10.1016/j.fsisyn.2020.06.005.This letter to the editor is published as Morrison, Geoffrey Stewart, et al. "Reply to Response to Vacuous standards–subversion of the OSAC standards-development process." Forensic Science International: Synergy 3 (2021): 100149. doi:10.1016/j.fsisyn.2021.100149. Posted with permission of CSAFE.This is an open access article under the CC BY-NC-ND license