“
Oui je sais” (yes, I know) is an old but still very true balad, sang by the French artist Jean Gabin (1904-1976).
“Yes, I know” is also what inspectors are sometimes told by individual researchers when inspecting an analytical laboratory on their compliance with Good Laboratory Practice (GLP), implicating that they are an expert in the field and are well trained to do the job. With a few examples below I want to illustrate that there is a definite need that experts check their professionalism by comparing their results with others.
- Yes, I know how to determine a limit of detection (LOD)...but, in a recent FP6 European project, LOD's differing by a factor of hundred were reported by different laboratories for the analysis of trace elements by ICP (Inductively Coupled Plasma).
- Yes, I know how to model a calibration line...but did the situation really improve since D. Kurz reported large discrepancies between the (linear) models developed by recognized experts in the field. More worrying was that these discrepancies also resulted in different answers reported back for a blind sample. (D. Kurtz (Ed). Trace Residue Analysis - Chemometric Estimations of Sampling, Amount and Error, ACS Symp. Series 284 (1985) p 187)
- Yes, I know how to perform a multivariate calibration, e.g. by Partial least Squares (PLS)...but the results reported by an SMT team of experts indicated that there is a diversity of opinions on how to analyze the same data leading to different results. (Network for Intercomparison of Chemometric Software and Techniques, IMT/SMT programme (1994-1998), Project PL97-9526)
Are professionals then afraid of organizing and participating in proficiency tests using “reference“ data (e.g. available from NIST) and to humbly admit that the last sentence of the song by Jean Gabin is all but true “Maintenant,.. je sais..., je sais qu'on ne sait jamais...“ (I know, I know one never knows..)