Question

_______ is used for expression of precision of a method.

• A. \( \text{Mean} \)
• B. \( \text{ Assay} \)
• C. \( \text{ CV} \)
• D. \( \text{Correlation coefficient} \)

Hint:

Think of% CV as a "consistency score" – a lower percentage means your results are more tightly clustered, indicating good precision.

Answer 1

The Correct Option is C

In the context of evaluating the precision of a method, the term used is the "Coefficient of Variation" or CV. Precision is a measure of how reproducible results are when repeated under unchanged conditions. Mathematically, the coefficient of variation is calculated as follows:

\[ \text{CV} = \left( \frac{\text{Standard Deviation}}{\text{Mean}} \right) \times 100\% \]

This formula quantifies the relative variability of the data in comparison to the mean, giving a percentage that reflects precision. A lower CV indicates higher precision, meaning data points are closely clustered around the mean.

Option	Description
\( \text{Mean} \)	The average value of a data set; not a precision indicator.
\( \text{Assay} \)	A procedure in chemistry to determine the content or quality of a substance; not specifically a measure of precision.
\( \text{CV} \)	The coefficient of variation; a statistical measure for precision.
\( \text{Correlation coefficient} \)	A measure of the strength and direction of a linear relationship between two variables; not used for precision of a method.