Power function graphs, critical error graphs, or OPSpecs charts are useful for making this assessment and documenting the appropriateness of the selected acceptability criteria.
Subsequent sections, "Learning Program Operation" and "Rule Selection Methodology", give a more general background with an outline of the selection procedure based on the OPSpecs chart concept, partly as excerpts from earlier publications.
Figure 4 is an OPSpecs chart showing the inaccuracy (on the "y" axis) and imprecision (on the "x" axis) allowable with various QC procedures.
The "edit comments" option is used to add comments to the report and the "select charts" option allows users to choose those power function graphs, critical error graphs, and OPSpecs charts to be included in the report.
The preponderance of the book serves to explain the OPSpecs Chart to the initiate (the first 15 chapters contain ~40 of these charts and 150 references to the charts).
The authors indirectly evaluated the conditional probability for one case of systematic error and one case of increased random error via their OPSpecs charts and concluded that the NCEP recommendations for precision and accuracy are inadequate.
The results of these calculations are presented in the form of an OPSpecs chart that displays the inaccuracy (y-axis) and imprecision (xaxis) that are allowable, given the quality required for the test and the known error detection capabilities of candidate control rules and numbers of control measurements.
In this study, OPSpecs charts were prepared to show the imprecision and inaccuracy that are allowable for common QC procedures with N = 2 to 4, 90% analytical quality assurance, and the stated NCEP analytical total error requirements and the clinical decision interval ([D.
The OPSpecs charts for the NCEP clinical quality requirements for TRIG, HDL-C, and LDL-C are shown in Fig.
Westgard] are taken from the Westgard, Smith, Mountain and Boss paper with N being derived from Westgard's OPSpecs analysis of power functions of averages of patient data.
The table of candidate QC procedures contains the power curves and OPSpecs calculation parameters for 94 different QC procedures, including: constant-limit single rules [1.
OPSpecs charts were prepared for the examples illustrated earlier by spreadsheet calculations of allowable imprecision and allowable inaccuracy for both the clinical model  and the analytical model .