THE EFFECT OF SEQUENTIAL PRESENTATION OF WINNING SYMBOLS ON THE COMMON SLOT MACHINE WAS EVALUATED. IT WAS FOUND THAT SS WHO SAW WINNING SYMBOLS EARLY IN THE OUTCOME SEQUENCE WERE MORE LIKELY TO CONTINUE PLAYING AFTER A REQUIRED NUMBER OF TRIALS THAN WERE THOSE WHO OBSERVED A COMPARABLE PROPORTION OF WINNING SYMBOLS LATER IN THE SEQUENCE. THE OUTCOME WAS DISCUSSED IN TERMS OF S'S EXPECTATIONS AND IN THE CONTEXT OF "HOPE" AND "DISAPPOINTMENT" AS THESE CONCEPTS ARE EMPLOYED IN MOWRER'S LEARNING THEORY. (PsycINFO Database Record (c) 2006 APA, all rights reserved)