Statistics Meeting Book (12-14-16)

AOAC INTERNATIONAL Memorandum

Date: December 13, 2016

To:

Statistics Working group on Intermediate Precision

From: Scott Coates

Intermediate Precision [ RSD i ]

1. Should AOAC specify/include Intermediate precision in method evaluations? a. Required in Appendix L: AOAC Recommended Guidelines for Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) Single-Laboratory Validation (attachment 1) b. Required or optional in validation manuscript ? c. In place of RSDr, or in addition to RSDr ? d. In SMPRs ? 2. Which definition to use? a. Appendix K: Guideline for Dietary Supplements and Botanicals includes a definition (attachment 2) but does not provide guidance for evaluation. b. Specific minimum requirements (minimum number of analysts, instruments, days, etc.)

3. Expected value?

a. Predicted RSDr is estimated as 2/3 * (PRSDR) . b. PRSDR = 2C^ – 0.15. c. Predicted RSD i ?

4. In which document should this guidance reside ?