round robin testing

**Round Robin Testing** is a **specific type of interlaboratory comparison where the same test specimen is circulated sequentially among participating laboratories** — each lab performs the same measurement procedure, reports results, and the data is analyzed to evaluate between-lab consistency and identify outliers. **Round Robin Protocol** - **Sample**: A stable, homogeneous sample is prepared — must not change during circulation. - **Circulation**: Sample travels Lab A → Lab B → Lab C → ... → Lab A (return check for sample stability). - **Blind Testing**: Labs may not know the reference value or other labs' results — prevents bias. - **Analysis**: ANOVA, z-scores, or $E_n$ numbers evaluate each lab's performance relative to the group. **Why It Matters** - **Tool Matching**: In semiconductor fabs, round robin testing validates CD-SEM, overlay, and defect tool matching across sites. - **Method Validation**: New measurement methods are validated by round robin — demonstrate reproducibility across laboratories. - **Standard Development**: Round robin data supports the development of measurement standards (SEMI, ISO, ASTM). **Round Robin Testing** is **the measurement relay race** — circulating a sample among labs to verify that everyone gets the same answer.