Kinsey and his co-workers wrote two books which became known as the Kinsey Reports. They were based on thousands of interviews with men (first report), and then women. The aim was to find out how widespread or differentiated human sexual practices were. He developed the Kinsey Scale to measure sexual orientation. On one end of the scale, at the value 0, the individual is entirely heterosexual. On the other end, at value 6, he or she has a purely homosexual orientation. Kinsey was bisexual.