Fig. 6
From: Review and interlaboratory comparison of the Oddy test methodology
PCA performed from the overall assessments in columns 4–12 of Table 8. The bottom and left axes of this biplot correspond to the institutions (I-VII). The top and right axes correspond to the variables (evaluations of P, T and U for each metal). These axes indicate the direction and strength of the variables in the space defined by PC1 and PC2. The variable axes help indicate which classifications explain the observed differences between institutions