In recent years, there has grown a variety of different ways to obtain estimations of what is called “Random Jitter” (Rj) and “Deterministic Jitter” (Dj). This discussion is about how to organize those methods into three basic categories, pertinent to three different sets of needs. Perhaps if nothing else, it will help the reader to keep the conflicting definitions and consequent differing measurement results from creating fear and doubt concerning jitter measurement. T E C H N I C A L B R I E F SIX TALES OF RJ AND DJ OR A DISCUSSION OF WHICH MEASUREMENT APPROACH IS BEST ADAPTED TO SPECIFIC NEEDS Dr. Martin Miller ……