Biographical evaluation (Arabic: عِلْمُ الرِّجال, translit.: `Ilm al-Rijāl), literally meaning 'Knowledge of Men' but more commonly understood as the Science of Narration, refers to a discipline of Islamic religious studies within hadith terminology in which the narrators of hadith are evaluated. Its goal is to distinguish authentic and reliable hadiths from unreliable hadiths in establishing the credibility of the narrators, using both historic and religious knowledge.