Sort each item by whether it is characteristic of the SOURCES available for medieval history or for contemporary history.

Medieval sources: A handful of charters surviving from one monastery, Archaeological evidence for diet and building materials

Contemporary sources: Mass-circulation newspapers held in national libraries, Systematic census and government statistical series, Photographic, film and later sound recording

The methodological consequence is the interesting part. Scarcity forces the medievalist to squeeze every source and to argue explicitly about representativeness. Abundance lets the contemporary historian find evidence for almost any thesis, which makes the principle of selection, rarely stated, the place where the interpretation actually happens.