Questions

Some questions and answers on trends, "Westgard Rules", manufacturer ranges, significant figures, quality requirements, and more. It's a real grab bag.

If you don't see the question that you'd like to see answered, please send it in to This email address is being protected from spambots. You need JavaScript enabled to view it.

Please Note: The Basic Method Validation manual is now in its FOURTH edition. The questions presented in this article are drawn from the first edition. Many of the answers here still apply, but some things, particularly on the regulatory side, have changed in the past 20 years.

This group of questions come from a set of students in Chem 555, a graduate course in Clinical Chemistry at West Chester University, West Chester, PA Dr. Al Caffo was the course instructor and an old friend from DuPont/Dade/Behring days (the good old days). It's been great to have this opportunity to discuss method validation practices.

It's time once again to post some of the questions we received in the last few months. These questions were important enough that we thought the answers should be shared with everyone. The definition of N and a run is discussed, as well as z-values, defect rates, external QC when there is no peer group, etc.

On March 5th, 2002, Dr. Westgard was the guest at the AACC's Expert Access Online. The topic was Six Sigma.