In forensic-evidence evaluation, practitioners assign a strength of evidence to forensic observations and analytical results, to address hypotheses at source or activity level. This assignment is based on the practitioner's assessment and, increasingly, on the computations of automatic likelihood-ratio methods. This chapter focuses on the validation of methods that automatically assign a strength of evidence at source level to the analytical results originating from the comparison of distinctive features of two specimens. It follows a Bayesian interpretation of probability and the recent guideline for evaluative reporting in forensic science in Europe. The Chapter offers guidance to forensic practitioners assessing the scope of validity and applicability of automatic likelihood-ratio methods as part of new methods. It reviews of the most important standards for validation along with the concepts of performance characteristics, performance metrics and validation criteria, which constitute the validation process. It discusses the measurement of performance of the evaluation methods and describes the primary and secondary characteristics used to assess the performance of these methods.