The interpretation of tool marks is an important component of many forensic investigations and can impact on a variety of disciplines, including anthropology, archaeology and pathology. Variations occur throughout the world in regard to qualifications and training requirements for a person to become a forensic tool mark examiner. The Scientific Working Group for Firearms and Toolmarks describe the tool mark analysis as being 'An empirical comparative analysis that can determine if a striated or impressed mark was produced by a particular tool'. Certification programmes in tool mark examination are offered to members of the Association of Firearm and Toolmark Examiners in an attempt to introduce some standardization to the discipline. Accurate and effective comparison skills are utilized when an opinion is sought as to the likelihood that a specific tool was responsible for the marks on a substrate.