Educational research
Educational research investigates how people learn. Literacy was the first starting-point. Before about 1470 all books were hand-written. Printing made the word visible. Before 1800 most ordinary people could not read or write. That was true for all countries. By 1900 most people in the most industrial countries could read. The Bible was one of the causes: people wanted to read the Bible in Christian countries. Just as important was industrialization. With industry grew a need for instruction, and there were printed rule books in key industries such as the railways. Church registers in England show increasing literacy as judged by the ability of men to sign their names. Previously, if a man signed with an X, a church clerk added his name.