Hadith same text are each counted as individual ahadith. If, say, ten companions record a text reporting a single incident in the life of Muhammad, hadith scholars can count this as ten hadiths. So Musnad Ahmad, for example, has over 30,000 hadiths—but this count includes texts that are repeated in order to record slight variations within the text or within the chains of narrations. Identifying the narrators of the various texts, comparing their narrations of the same texts to identify both the soundest reporting of a text and the reporters who are most sound in their reporting occupied experts of hadith
Introduction to the Science of Hadith adding six terms in the process). The first pertains to the "matn" (text) of the hadith and its three divisions and 30 types. The three divisions are "ṣaḥīḥ", "ḥasan", and "ḍa`īf". The thirty types include those mentioned in hadith terminology and others. The second deals with the "isnād" (chain of narration) and comprises 11 types. These types generally fall within the discipline of biographical evaluation. The third category includes six types: the qualifications necessary for conveying hadith, the manners in which they are transmitted, the transcription of hadith, and the etiquette of the narrator and of the student. The fourth