Historiography is the study of the methods of historians in developing history as an academic discipline, and by extension is any body of historical work on a particular subject. The historiography of a specific topic covers how historians have studied that topic using particular sources, techniques, and theoretical approaches. Historians who are researching a particular era of history can often walk away based on their research with different opinions, and such opinions will lead to many heated debates. Such debates will lead to Historiographical papers written looking at what other historians have said about their given area of research. Historiography has several elements, but for the purposes of a researcher trying to situate his work in the context of other historians' work on a particular topic, the most useful thing is the historiographic essay or review article that summarizes changing ideas about and approaches to the topic. A really good historiographic essay will also address why historians' ideas have changed.