•When using data from
different sampling networks, it is important
to consider
–The multiple sampling networks from which data were drawn for these analyses vary in their objectives and sampling
and analytical methods. Data
may not always be comparable.
–Sampling, analysis, method detection limits, objectives, site characteristics, etc. have changed over time. Care
is needed in
interpreting temporal and spatial trends.
•Analysts need to
gather, and understand, all metadata prior
to conducting analyses.