Dr. Noah Tahl, quality administrator for St. Recover in the Long Run Hospital, recently went to a half-day seminar in Hawaii, entitled “Quality Tools for the Health Care Industry.” While Dr. Tahl is highly discriminating about the location of training sessions he attends, the content is generally a less critical factor in his decision.

When the seminar opened at 1:00 p.m., Dr. Tahl had just finished playing eighteen holes of golf and he was having a difficult time staying awake. The instructor began to talk about the usefulness of cause-and-effect charts, and soon Dr. Tahl's head dropped and he was out. By the time he was jolted awake some time later, the instructor had moved on to Pareto charts, and was completing the section with an exercise that involved using M&Ms to illustrate the Pareto diagram. Believing that this exercise applied to cause-and-effect diagrams, Tahl took copious notes so that he could put on a seminar at the hospital upon his return.

One week later, he gathered his staff to provide a lecture on cause-and-effect charts, prepared to dazzle them with the M&M exercise.

Confused by his presentation, one of his staff members diffidently asked whether this was really a cause-and-effect diagram, or whether it might instead be a Pareto chart. “There are variations on the cause-and-effect diagram,” Dr. Tahl responded impatiently, “and this is one of them. They all prove the same thing.”  Are cause-and-effect diagrams used for the same purposes that Pareto data is gathered?