Which of the following is an acceptable method to demonstrate continued performance?

• A. Another initial demonstration of capability
• B. Acceptable analysis of blind performance samples
• C. Four consecutive laboratory control samples
• D. Ten authentic samples with results indistinguishable from another trained analyst

Answer: (D)

Maintaining continued performance means proving you can keep producing accurate results over time, across real-world samples and varying conditions. The strongest way to show this is by analyzing a set of authentic samples and comparing your results to those of another trained analyst. When you can obtain ten real samples and your results align with a peer’s results, it demonstrates sustained accuracy and consistency in your work, not just a one-time capability.

Other methods fall short for ongoing verification because they don’t provide the same level of persistent, cross-check evidence. Repeating an initial capability check shows you could perform at one point, but it doesn’t establish continued proficiency. Blind performance samples test accuracy in a controlled way, yet they don’t necessarily reveal how you perform across many real cases over time. Using a few consecutive control samples demonstrates precision within a single run but doesn’t reflect performance on real-world specimens across periods.