TY - JOUR A1 - Cortez, L. A1 - Squirrel, A. A1 - Boley, N. A1 - Garcia, C. A1 - van Berkel, P.M. A1 - Boisson, G. A1 - Foster, H. A1 - Papadakis, I. A1 - Steffen, Bernd T1 - How to interpret information from proficiency test exercises concerning the relative performance of accredited laboratories JF - Accreditation and quality assurance N2 - If the results from various proficiency tests are used to compare the performance of accredited and non-accredited laboratories, great care must be taken not to come to contradicting conclusions when interpreting them. This paper intends to draw the attention to various aspects that should be taken into account when trying to make conclusions from the relative performance of accredited laboratories in proficiency testing. KW - Proficiency test exercises KW - Accredited laboratories KW - Relative performance PY - 2003 DO - https://doi.org/10.1007/s00769-003-0674-0 SN - 0949-1775 SN - 1432-0517 VL - 8 IS - 11 SP - 511 EP - 513 PB - Springer CY - Berlin AN - OPUS4-1843 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Golze, Manfred A1 - Müller, Andreas A1 - Recknagel, Angelika A1 - Steffen, Bernd A1 - Boley, N. A1 - van der Veen, A. T1 - Interlinkages and recognition of proficiency testing schemes JF - Accreditation and quality assurance PY - 2000 SN - 0949-1775 SN - 1432-0517 PB - Springer CY - Berlin AN - OPUS4-1063 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Boley, N. A1 - van der Veen, A.M.H. A1 - Robouch, P. A1 - Golze, Manfred A1 - van de Kreeke, Johannes A1 - Örnemark, U. A1 - Tylee, B. T1 - Comparability of PT schemes - what did we learn from COEPT? JF - Accreditation and quality assurance N2 - Abstract The use of proficiency testing schemes (PTS) by laboratories as an integral part of their quality system has been increasing in recent years. Accreditation bodies, regulators and the laboratories’ customers are increasingly using results from PTS in their relationship with laboratories. There are many PTS available in Europe in analytical chemistry; EPTIS indicates over 400. The comparability of these PTS is now a real issue, as many organisers of PTS move into new markets. The COEPT project has systematically demonstrated (in four technical sectors – water, soil, food and occupational hygiene), that there are many similarities between PTS in each sector. For example, nearly all use the z-score as a performance index. One significant difference between many PTS is the value used for the term s in the z-score equation, and this gives a range of evaluations for the same data point. Despite this, the agreement between PTS in the same sector for the evaluation of data is approximately 85%. COEPT has given us a basis for establishing the comparability of PTS and showing us where further harmonisation could occur. KW - Proficiency testing KW - Comparability KW - Harmonisation PY - 2006 SN - 0949-1775 SN - 1432-0517 VL - 11 IS - 8-9 SP - 391 EP - 399 PB - Springer CY - Berlin AN - OPUS4-14162 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -