Estimation of accordance and concordance in inter-laboratory trials of analytical methods with qualitative results.

In this short communication, we discuss alternative ways to estimate accordance and concordance, which are, for qualitative methods, the analogues of the well-known concepts repeatability and reproducibility. We argue that estimators in a random framework appear to be more appropriate than the estimators in a fixed framework as they were originally introduced by Langton et al. [International Journal of Food Microbiology 79 (2002) 171]. A simple example of their application is given.