From
Wikipedia ...
There are two basic issues involved in historiography. (Breisach, 1994) First, the study of the development of history as an academic discipline over time, as well as its development in different cultures and epochs. Second, the study of the academic tools, methods and approaches that have been and are being used, including the historical method.
The term "historiography" can also be used to refer to a specific body of historical writing that was written during a specific time concerning a specific issue. For instance, "medieval historiography during the 1960s" would be taken to mean the methodological approaches and ideas about medieval history that were developed during that decade.
Conal Furay and Michael J. Salevouris define historiography as "the study of the way history has been and is written — the history of historical writing... When you study 'historiography' you do not study the events of the past directly, but the changing interpretations of those events in the works of individual historians."
I suspected that you were inquiring as to evidence.