Common cause vs. special cause variation, aren’t they the same thing? At first glance, you’d be allowed to think so. However, as with any part of the production cycle, there is a reason for ...

In the summer of 1970, Gardner took what he called "the biggest gamble of my career," and founded Common Cause, a citizen's ... that there were a lot of strong special interests, but no one ...

2 types of variation and how we distinguish between common and special cause variation, along with how to create a rational subgroup. We also cover the equations and constants for the X-bar and R ...