Form criticism is a method of biblical criticism that classifies units of scripture by literary pattern (such as parables or legends) and that attempts to trace each type to its period of oral transmission. Form criticism seeks to determine a unit's original form and the historical context of the literary tradition. Hermann Gunkel originally developed form criticism to analyze the Hebrew Bible. It has since been used to supplement the documentary hypothesis explaining the origin of the Pentateuch (the first five books of the Hebrew Bible) and to study the Christian New Testament.