The 4th edition of the Reference Manual on Scientific Evidence updates the topics covered in the 2011 3rd Edition with the latest science and expands to discuss many new topics, identifying issues that will be useful to judges and others in the legal profession. This valuable reference examines pivotal issues in the areas of science most often subject to dispute, discussing assessment of a case's needs and evaluating experts and data. The Reference Manual on Scientific Evidence will support judges and other legal professions to ensure that science presented in the courtroom can be understood in the lens of the scientific method and reasoning. First published in 1994 by the Federal Judicial Center, the Reference Manual on Scientific Evidence has been relied upon in the legal and academic communities and is often cited by various courts and others. Judges faced with disputes over the admissibility of scientific and technical evidence refer to the manual to help them better understand and evaluate the relevance, reliability, and usefulness of the evidence being proffered. The manual is not intended to tell judges what is good science and what is not. Instead, it serves to help judges identify issues on which experts are likely to differ and to guide the inquiry of the court in seeking an informed resolution of the conflict.