"Asmā' ar-rijāl" is a term used by scholars of Hadīth. It refers to the biographical evaluation of the narrators of Hadīth, which is an important aspect of the science of Hadīth. This evaluation includes examining the reliability, integrity, and accuracy of the narrators to determine the authenticity of a Hadīth. Scholars use this information to determine whether a Hadīth is Sahīh (authentic) or Da'īf (weak).