- Are all labs equivalent?
- What labs have between-lab problems (reproducibility)?
- What labs have within-lab problems (repeatability)?
- What labs are outliers?
- Vertical Axis: Response for Run 1
- Horizontal Axis: Response for Run 2
- Plot Character: Laboratory ID
- Not all labs are equivalent
- Lab 4 is biased low
- Lab 3 has within-lab variability problems
- Lab 5 has an outlying run
- NIST/SEMATECH Handbook Chapter:
Exploratory Data Analysis
- Youden (1959), Graphical Diagnosis of
Interlaboratory Test Results, Industrial
Quality Control, 15, pp. 24-28.
- Chambers, Cleveland, Kleiner, and Tukey (1983),
Graphical Methods for Data Analysis,