Data Quality Estimates in the NGS

Data quality descriptions in this table are subjective determinations based on the authors' experience with these methods. They are based on how well the method is expected to perform for stream sediment samples with typical compositions for the United States. Opinions take into consideration known analytical problems, published detection limits, and past experience in comparing data from multiple analytical methods. The crude categories used to describe data quality are: Future versions of this report will contain quantitative discussions of accuracy and precision for each method.