Which term describes the variability among results obtained from repeated testing of the same sample within the same lab?

• A. Repeatability
• B. Reproducibility
• C. Reliability
• D. Agreement

Answer: (A)

Repeatability is the variability observed when the same sample is tested multiple times in the same lab with the same equipment and method under the same conditions. It reflects how precise the measurement is within those controlled settings; smaller spread across repeated runs means higher repeatability, while a larger spread indicates poorer repeatability. Reproducibility would involve testing across different labs, instruments, or operators and generally shows more variation. Reliability and agreement refer to broader notions of consistency and agreement between methods or observers, not specifically to repeated testing within one lab.