ASTM D2777-98

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D 2777 – 98
Standard Practice for
Determination of Precision and Bias of Applicable Test
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Methods of Committee D-19 on Water
This standard is issued under the fixed designation D 2777; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (ϵ) indicates an editorial change since the last revision or reapproval.
1. Scope the precision and bias statement required in each test method.
Ifthestudydoesnotsatisfythecurrentminimumrequirements
1.1 This practice establishes uniform standards for estimat-
for a collaborative study, a statement listing the study’s
ing and expressing the precision and bias of applicable test
deficiencies and a reference to this paragraph shall be included
methods for Committee D-19 on Water.
in the precision and bias statement as the basis for an
1.2 Except as specified in 1.3, 1.4, and 1.5, this practice
exemption from the current requirements.
requires the task group proposing a new test method to carry
1.5 This paragraph relates to special exemptions not clearly
out a collaborative study from which statements for precision
acceptable under 1.3 or 1.4. With the approval of Committee
(overall and single-operator standard deviation estimates) and
D-19 on the recommendation of the Results Advisor and the
biascanbedeveloped.Thispracticeprovidesgeneralguidance
Technical Operations Section of the Executive Subcommittee
to task groups in planning and conducting such determinations
of Committee D-19, a statement giving a compelling reason
of precision and bias.
why compliance with all or specific points of this practice
1.3 If a full-scale collaborative study is not technically
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cannot be achieved will meet both ASTM requirements (1)
feasible, due to the nature of the test method or instability of
andtherelatedrequirementsofthispractice.Precisionandbias
samples, the largest feasible scaled-down collaborative study
statements authorized by this paragraph shall include the date
shallbeconductedtoprovidethebestpossiblelimitedbasisfor
of approval by Committee D-19.
estimating the overall and single-operator standard deviations.
1.6 In principle, all test methods are covered by this
1.3.1 Examples of acceptable scaled-down studies are the
practice.
local-area studies conducted by Subcommittee D19.24 on
1.7 In Section 11 this practice shows exemplary precision
microbiological methods because of inherent sample instabil-
and bias statement formats for: (1) test methods yielding a
ity. These studies involve six or more completely independent
numerical measure, (2) test methods yielding a non-numerical
local-area analysts who can begin analysis of uniform samples
report of success or failure based on criteria specified in the
at an agreed upon time.
procedure, and (3) test methods specifying that procedures in
1.3.2 If uniform samples are not feasible under any circum-
anotherASTM test method are to be used with only insignifi-
stances, a statement of single-operator precision will meet the
cant modifications.
requirements of this practice. Whenever possible, this state-
1.8 All studies, even those exempt from some requirements
mentshouldbedevelopedfromdatageneratedbyindependent
under 1.3 or 1.5, shall receive approval from the Results
multiple operators, each doing replicate analyses on indepen-
Advisor before being conducted (see Section 8) and after
dent samples of a specific matrix type, which generally fall
completion (see Section 12).
within specified concentration ranges (see 7.2.5.2( 3)).
1.3.3 Thispracticeisnotapplicabletomethodologyinvolv-
2. Referenced Documents
ing continuous sampling or measurement, or both, of specific
2.1 ASTM Standards:
constituents and properties.
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D1129 Terminology Relating to Water
1.3.4 This practice is also not applicable to open-channel
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D1141 Specification for Substitute Ocean Water
flow measurements.
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D1193 Specification for Reagent Water
1.4 A collaborative study that satisfied the requirements of
D4375 Terminology for Basic Statistics in Committee
the version of this practice in force when the study was
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D-19 on Water
conducted will continue to be considered an adequate basis for
D5790 TestMethodforMeasurementofPurgeableOrganic
Compounds in Water by Capillary Column Gas
1
This practice is under the jurisdiction ofASTM Committee D-19 onWater and
is the direct responsibility of Subcommittee D19.02 on General Specifications,
2
Technical Resources, and Statistical Methods. The boldface numbers in parentheses refer to the list of standards at the end of
Current edition approved Jan. 10, 1998. Published October 1998. Originally this practice.
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published as D2777–69T. Last previous edition D2777–96. Annual Book of ASTM Stand
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