Data Quality, Performance, and Uncertainty in Taxonomic Identification for Biological Assessments
J. N. Am. Benthol. Soc., 2008, 27(4):906–919 Ó 2008 by The North American Benthological Society DOI: 10.1899/07-175.1 Published online: 28 October 2008 Data quality, performance, and uncertainty in taxonomic identification for biological assessments 1 2 James B. Stribling AND Kristen L. Pavlik Tetra Tech, Inc., 400 Red Brook Blvd., Suite 200, Owings Mills, Maryland 21117-5159 USA Susan M. Holdsworth3 Office of Wetlands, Oceans, and Watersheds, US Environmental Protection Agency, 1200 Pennsylvania Ave., NW, Mail Code 4503T, Washington, DC 20460 USA Erik W. Leppo4 Tetra Tech, Inc., 400 Red Brook Blvd., Suite 200, Owings Mills, Maryland 21117-5159 USA Abstract. Taxonomic identifications are central to biological assessment; thus, documenting and reporting uncertainty associated with identifications is critical. The presumption that comparable results would be obtained, regardless of which or how many taxonomists were used to identify samples, lies at the core of any assessment. As part of a national survey of streams, 741 benthic macroinvertebrate samples were collected throughout the eastern USA, subsampled in laboratories to ;500 organisms/sample, and sent to taxonomists for identification and enumeration. Primary identifications were done by 25 taxonomists in 8 laboratories. For each laboratory, ;10% of the samples were randomly selected for quality control (QC) reidentification and sent to an independent taxonomist in a separate laboratory (total n ¼ 74), and the 2 sets of results were compared directly. The results of the sample-based comparisons were summarized as % taxonomic disagreement (PTD) and % difference in enumeration (PDE). Across the set of QC samples, mean values of PTD and PDE were ;21 and 2.6%, respectively.
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