Prescription and description
Descriptive approaches
Linguistics has always required a process called description, which involves observing language and creating conceptual categories for it without establishing rules of language.[citation needed] However in the 16th and 17th centuries, in which modern linguistics began, projects in lexicography provided the basis for 18th and 19th century comparative work - mainly on classical languages. By the early 20th century, this focus shifted to modern languages as the descriptive approach of analyzing speech and writings became more formal. Despite this following appearance, the more fundamental descriptive method was used prior to the advent of prescription, and is the key to linguistic research. The reason for this priorhood is that linguistics, as any other branch of science, requires observation and analysis of a natural phenomenon, such as the order of words in communication, which may be done without prescriptive rules. In descriptive linguistics, nonstandard varieties of language are held to be no more or less correct than standard varieties of languages. Whether or not observational methods are seen to be more objective than prescriptive methods, the outcomes of using prescriptive methods are also subject to description.