1. One characteristic that is evaluated during the method qualification or validation of a test method used in Quality Control is Linearity. What is linearity and why is it important to test this characteristic when qualifying or validating some analytical test methods? (Hint: Refer to ICH Q2 (R1): Validation of Analytical Procedures: Text and Methodology)

2. Why do some analytical test methods used in Quality Control need to be demonstrated to be stability-indicating? Also, how would you show that a method is stability-indicating?

3. A Quality Control laboratory is observing a significant number of out of specification (OOS) test results for one test method. However, during the OOS investigations, it was found that the test results were invalid. Thus, the OOS investigations were closed after the Phase 1 investigation. The test method is a chromatography-based method, and one system suitability criterion called peak resolution continues to fail which makes the test results invalid. How should you proceed? (Do not worry if you are unfamiliar with chromatographic methods. The point is that method system suitability criteria are continuing to fail.)

4. You suspect that a QC Analyst who reports to you is falsifying data. This analyst is generating results that greatly exceed other analysts who perform the same method. Also, you notice that the volume of stock reagents that are used to perform the test do not change after the analyst in question finishes their work. What should you do?