Historians analyze the information available to them to develop theories about past events, experiences, ideas, and movements. Depending on their interests, historians may consider a variety of issues and sources related to economics, politics, social issues, science, the military, gender, the family, or popular culture.

Historians do not simply record what happened at a particular time; rather, they attempt to explain why or how events occurred and to place those events in a larger context. For example, a historian writing about women in the British military during World War II would not simply describe the positions women held in the armed forces; through an analysis of the available information, the historian might develop a theory about why women were authorized to hold certain jobs and not others and how changes to women’s roles affected the evolution of the women’s rights movement in the decades that followed.