Historiography is the study of historical writing, or the history of history. Conal Furay and Michael J. Salevouris define it as "the study of the way history has been and is written - the history of historical writing... When you study "historiography" you are studying how individual historians have interpreted and presented specific subjects... (The Methods and Skills of History, p. 227)
Jules R. Benjamin has this to say "historiography examines changes in the methods, interpretations, and conclusions of earlier generations of historians. Often, earlier studies of historical topics reached conclusions that historians today find surprising." (A Student's Guide to History, p. 5).
In a historiographical essay the writer examines, summarizes,and analyzes the work of other writers on a topic by studying their interpretations and conclusions.