Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:1850:p104
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 1850 (pt 104/117)
Character Range: 657654–660720

sampling methods
    * potential constraints to carrying out the investigation, such as access, presence of infrastructure, health and safety issues.
Step 4 of the DQO process should assist in developing:
    * a detailed description of the spatial and temporal boundaries of the problem
    * an understanding of any practical constraints that may interfere with the assessment.

    18.2.5      Step 5: Develop the analytical approach (or decision rule)
The fifth step involves defining the parameter of interest, specifying the action level, and integrating information from Steps 1–4 into a single statement that gives a logical basis for choosing between alternative actions. Acceptable limits should be defined for the following:
    * chemicals of concern detected in field blanks, rinsate blanks, volatile-spiked trip samples, laboratory method blanks
    * recovery of matrix spike additions, surrogate spike additions, laboratory control samples
    * relative percent differences (RPDs) of matrix spike and matrix spike duplicates.
Step 5 of the DQO process should assist in producing:
    * the statistical parameter (the parameter of interest) that characterises the population
    * confirmation that the action level exceeds measurement detection limits
    * an 'if …, then …' statement that defines the conditions that would cause a decision-maker to choose from alternative actions.

    18.2.6      Step 6: Specify the performance or acceptance criteria
The sixth step involves specifying the decision-maker's acceptable limits on decision errors, which are used to establish performance goals for limiting uncertainties in the data. (For more information about decision errors and decision-making, see notes at the end of this Appendix). Some of the matters to consider at this stage include:
    * determination of the possible range of the parameter of interest
    * identification of decision errors and formulation of the null hypothesis
    * specification of a range of possible parameter values where the consequences of decision errors are relatively minor (grey region)
    * assignation of probability values to points above and below the action level that reflect the tolerable probability for the occurrence of decision errors.
Step 6 of the DQO process should assist in calculating the decision-maker's tolerable decision error rates based on a consideration of the consequences of making an incorrect decision.

    18.2.7      Step 7: Optimise the design for obtaining data
The seventh step involves identifying the most resource-effective sampling and analysis design for generating the data that is required to satisfy the DQOs.
Step 7 of the DQO process should assist in developing:
    * the most resource-effective design for the study that is expected to achieve the DQOs
    * the optimum manner in which to collect the data required to meet the objectives for the assessment and which will meet the project DQOs
    * the SAQP.

18.3          Notes about decision errors and decision-making
Decision errors are incorrect