Branch of Quality Systems


Time Series Charts

The Time Series Charts
The charts provide OBSP recovery information for every analyte at different concentrations for every schedule OBSP assesses. The charts exhibit a Locally Weighted Scatterplot Smoothing (LOWESS) line. This line is used to help observe patterns and trends of the data over time. The time series charts also show bias and variability of the OSBP data. The most current time series charts in the table below will be overwritten periodically and will contain data that is currently being reviewed. All data is provisional and may change if the OBSP deems necessary.

There are two tables provided at the bottom of every time series chart that show statistical summaries.

Plotted Points Statistics Table
Description of the OBSP QA recoveries grouped by concentration level. The statistics in the table: mean, median, standard deviation and F-pseudosigma define bias and variability of the OBSP recoveries.

Sample Statistics Table
Counts (N) - The quantity of the variety of items.
Plotted - This number equals the total number in the above table.
Estimated Values - There are a number of reasons the laboratory will estimate (E) a result. If there are 100% of the results estimated the analyte is identified as a permanently estimated compound (analyte name in time series chart will be red).
Deleted Values - The laboratory may delete an entire sample or a single analyte for a number of reasons.
Spiked, Censored - A term for those samples that were spiked and correctly reported as less than a reporting level (possibly a raised reporting level) - the expected concentration was at a lower concentration than the censored result provided by the laboratory.
Spiked - The number of times the OBSP has submitted this analyte to the NWQL.
False Negative - The number of times the laboratory reports this analyte as not present in the sample when it is there.
Not Spiked - The number of times the OBSP has submitted a sample to the appropriate schedule, without this analyte.
False Positive - The number of times the laboratory reports this analyte as present when it is not in the sample.

Most current Time Series Charts
Time Series Charts January 2011 to December 2016
Time Series Charts January 2010 to December 2015
Time Series Charts January 2009 to December 2014
Time Series Charts January 2008 to December 2013
Time Series Charts January 2007 to December 2012
Time Series Charts January 2006 to December 2011
Time Series Charts January 2005 to December 2010
Time Series Charts January 2004 to December 2009
Time Series Charts January 2003 to December 2008
Time Series Charts January 2002 to December 2007
Time Series Charts January 2001 to September 2006
Time Series Charts January 2001 to September 2005
Time Series Charts January 1999 to September 2004
Time Series Charts January 1999 to September 2003

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Page Last Modified: March 1, 2017