[US Geological Survey]

Standard Reference Sample Project

Inter-laboratory Comparison Study Results

We have completed the development of new webpages (beginning with the Spring 2005 study). The biggest change is that laboratories are no longer rated. The individual laboratory performance pages display two frequency diagrams showing the distribution of your z-values and percent differences. The data tables have z-values >|6| and % differences >|20| highlighted to help you identify outliers.

Choose a Round

New Style Reports

Fall 2009 ( M-192 T-199 Hg-49 P-53 N-103 N-104 )

Spring 2009 ( M-190 T-197 Hg-48 P-52 N-101 N-102 )

Fall 2008 ( M-188 T-195 Hg-47 P-51 N-99 N-100 )

Spring 2008 ( M-186 T-193 Hg-46 P-50 N-97 N-98 )

Fall 2007 ( M-184 T-191 Hg-45 P-49 N-95 N-96 )

Spring 2007 ( M-182 T-189 Hg-44 P-48 N-93 N-94 )

Fall 2006 ( M-180 T-187 Hg-43 P-47 N-91 N-92 )

Spring 2006 ( M-178 T-185 Hg-42 P-46 N-89 N-90 )

Fall 2005 ( M-176 T-183 Hg-41 P-45 N-87 N-88 )

Spring 2005 ( M-174 T-181 Hg-40 P-44 N-85 N-86 )

Old Style Reports

Fall 2004 ( T-179 M-172 P-43 N-83 N-84 Hg-39 )

Spring 2004 ( T-177 M-170 P-42 N-81 N-82 Hg-38 )

Fall 2003 ( T-175 M-168 P-41 N-79 N-80 Hg-37 )