Premise: The earliest texts of William Shakespeare's works were published during the 16th and 17th centuries in quarto or folio format. Folios are large, tall volumes; quartos are smaller, roughly half the size (see Book size). The publications of the latter are usually abbreviated to Q1, Q2, etc., where the letter stands for "quarto" and the number for the first, second, or third edition published.
Hypothesis: They were a fun thing to read