 In linguistics, the goal of collecting corpus data is to identify and organize a representative sample of a written and/or spoken variety from which characteristics of the entire variety or genre can be induced. Concordances of word usage in linguistic context have long been used to aid in the translation and interpretation of literary and sacred texts of particular authors (e.g. Plato, Aristotle, Aquinas) and of particular texts (e.g. the Torah, the rest of the Old Testament, the Gospels, the Epistles). Formal textual criticism, the identification of antecedently existing oral traditions that were later redacted into Biblical texts, and author identification (e.g. figuring out which of the Epistles were written by Paul and which were probably not) began to develop in the late 19th century.