A study of assessors'' performance using graphical methods

The performance of a sensory panel is studied through analysis of variance and in particular the assessors × products interaction. A graphic can illustrate the partitioning of the interaction by a sum of distances between the assessors. The decomposition of the sum of the product effect plus the interaction allows a vector representation of the assessors. These vectors are classified with an original method in order to point out homogeneous sub-panels. The new classification allows aggregation of groups only when all the correlations between assessors are greater than a threshold.