Laundry lists, internal memos, even government files have disappeared. Even if historians had all of the scraps of paper, we wouldn't have the whole story because many aspects of the past are never written down and the past is no more clear-cut than the present. Think about your own life. Or would they miss the conversations with your loved ones, the exhaustion of the semester's end, and your feelings for cafeteria food. Historians fill gaps in the sources through a variety of methods, many of which rest on the historian's creativity.
Historians use quantitative and qualitative methods.
Historians have used marriage registers to figure out literacy rates. Because people in Britain learned to read before they learned to write, the ability to write with rudimentary skill meant they had some ability to read. By adding up people's ability to sign their name, historians could then quantify literacy rates. Historians have used cook books to explore the economic ties between empire and England in the nineteenth century. Recipes containing curry, mangoes, and sugar cane indicate a heavy reliance on colonial products.