ABRAHAM WALD'S recent book, Statistical Decision Functions presents a new theory of the foundations of statistics.'The vigorous exploration of this theory was begun by Professor Wald five or six years ago and is being continued under his leadership. Since almost all published treatments of this theory known to me, including this one, are mathematically forbidding;" and since the theory promises to be of great interest to all statisticians, it seems appropriate to attempt an informal exposition of it.