What type of plot is best for comparing precision and accuracy among laboratories?

The Tonks-Youden plot is an effective tool for comparing precision and accuracy among laboratories because it simultaneously represents both the accuracy (systematic error) and precision (random error) of measurements. This type of plot allows for the visual assessment of results from multiple laboratories by plotting the means and standard deviations of their results against a reference mean. Each laboratory's results can be plotted as points on this graph, making it easy to identify outliers or labs that show poor precision or accuracy.

In the context of laboratory performance evaluation, the Tonks-Youden plot provides a clear visualization of how various labs compare, indicating whether results are clustered together (indicating good precision) and close to the reference value (indicating good accuracy). This aspect of the plot is particularly valuable for quality control and inter-laboratory comparisons, as it emphasizes both dimensions of performance in a single, interpretable format.

Other plot types serve different purposes. For example, the Levy-Jennings chart is excellent for monitoring the performance of a laboratory over time but is focused on within-laboratory precision and accuracy rather than comparisons across different labs. Cusum plots show cumulative data which can indicate trends over time but are not specifically designed for direct comparisons among multiple laboratories. Linear regression