Historiography studies the processes by which historical knowledge is obtained and transmitted. Broadly speaking, historiography examines the writing of history and the use of historical methods, drawing upon such elements such as authorship, sourcing, interpretation, style, bias, and audience. The word historiography can also refer to a body of historical work. As the tools of historical investigation have changed over time and space, the term itself bears multiple meanings and is not readily associated with a single all-encompassing definition.