Premium
The Geo PT Proficiency Testing Scheme for Laboratories Routinely Analysing Silicate Rocks: A Review of the Operating Protocol and Proposals for its Modification
Author(s) -
Thompson Michael,
Webb Peter C.,
Potts Philip J.
Publication year - 2015
Publication title -
geostandards and geoanalytical research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.037
H-Index - 73
eISSN - 1751-908X
pISSN - 1639-4488
DOI - 10.1111/j.1751-908x.2014.00343.x
Subject(s) - protocol (science) , scheme (mathematics) , dual (grammatical number) , computer science , silicate , reliability engineering , statistics , mathematics , medicine , engineering , chemical engineering , pathology , art , mathematical analysis , alternative medicine , literature
The Geo PT proficiency testing programme for geochemical laboratories has been operating for nearly 20 years. This review, based on an analysis of accumulated data and extensive experience, examines whether the protocol followed during this period continues to be appropriate. Possible changes that might be considered for future implementation are examined, in particular the procedures for calculating assigned values, target values, z ‐scores and the applicability of dual fitness‐for‐purpose criteria. We conclude that the existing protocol remains largely appropriate and effective, but propose that a single fitness‐for‐purpose criterion be adopted, with an option for laboratories to recalculate their z ‐scores if the criterion is inappropriate for their requirements.