Quality control and quality assurance / Контроль и обеспечение качества (QA/QC)

A thorough program of quality assurance/quality control (QA/QC) will enable collection of meaningful and scientifically credible samples. Quality assurance (QA) includes a range of management and technical practices designed to guarantee that the delivered product is commensurate with the intended use. For environmental- or discharge-related studies, QA ensures that the data are of adequate scientific credibility to permit statistical interpretations that lead to resource-use management decisions. 

One of the most important aspects of QA is quality control (QC). QC includes specific formal goals (called data quality objectives, or DQOs), collection of data to assess data quality, the statistical assessment of the data quality, and the remedial measures taken whenever the DQOs are not realized.

A successful program of QA/QC not only ensures that the sampling process is in control but also presents estimates of the sampling error, especially sampling variance.

If some component of a sampling program is found not to be in control, then remedial response must be immediately initiated as soon as the problem is discovered, and both the problem and the remedial response must be thoroughly documented. Timely feedback communication between samplers and analysts is essential once a problem has been identified. <...>