1. Why are there different types of interlaboratory comparisons?

For many accredited laboratories, participation in CIL is vital. For example, biomedical analysis laboratories must take part in "quality control", managed by the Société française de biologie clinique, to be allowed to operate.

Proficiency testing is organized by specialized bodies. In France, these are mainly non-profit associations set up by a group of laboratories or professionals. Fees are charged. In most cases, the laboratory is a member of the association, and receives a sample of a work material at regular intervals, on which it generally takes a single measurement using its own operating procedure.

For these associations, the notion of consensus is very important, not only for selecting the types of materials to be tested, but also for interpreting the results and assessing the laboratory's "suitability" to carry out a given analysis...