ASTM E456-13A(2017)e2
(Terminology)Standard Terminology Relating to Quality and Statistics
Standard Terminology Relating to Quality and Statistics
SCOPE
1.1 This standard is the general terminology standard for terms defined in the standards of Committee E11 on Quality and Statistics.
1.2 A term in this standard which lists an attribution to an E11 technical standard indicates that the standard is normative for that term. Any changes in the term definition in the normative standard will be editorially changed in this standard. Any terms added to an E11 standard will be editorially added to this standard with an attribution to that standard.
1.3 Term definitions that are similar to ISO 3534 will be noted in this standard, but ISO 3534 will not be considered normative for any E11 terms.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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´2
Designation: E456 − 13a (Reapproved 2017) An American National Standard
Standard Terminology
Relating to Quality and Statistics
This standard is issued under the fixed designation E456; 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 (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
ε NOTE—Reapproved with new terms added and other terms corrected editorially in October 2017.
ε NOTE—New terms were added and other terms were corrected editorially in April 2018.
1. Scope Results of Probability Sampling
E177Practice for Use of the Terms Precision and Bias in
1.1 This standard is the general terminology standard for
ASTM Test Methods
terms defined in the standards of Committee E11 on Quality
E178Practice for Dealing With Outlying Observations
and Statistics.
E691Practice for Conducting an Interlaboratory Study to
1.2 A term in this standard which lists an attribution to an
Determine the Precision of a Test Method
E11 technical standard indicates that the standard is normative
E1169Practice for Conducting Ruggedness Tests
for that term. Any changes in the term definition in the
E1325Terminology Relating to Design of Experiments
normativestandardwillbeeditoriallychangedinthisstandard.
E1402Guide for Sampling Design
Any terms added to an E11 standard will be editorially added
E1488GuideforStatisticalProcedurestoUseinDeveloping
to this standard with an attribution to that standard.
and Applying Test Methods
1.3 Term definitions that are similar to ISO3534 will be
E1994Practice for Use of Process Oriented AOQL and
noted in this standard, but ISO3534 will not be considered
LTPD Sampling Plans
normative for any E11 terms.
E2234Practice for Sampling a Stream of Product by Attri-
1.4 This international standard was developed in accor-
butes Indexed by AQL
dance with internationally recognized principles on standard-
E2281Practice for Process Capability and Performance
ization established in the Decision on Principles for the
Measurement
Development of International Standards, Guides and Recom-
E2282Guide for Defining the Test Result of a Test Method
mendations issued by the World Trade Organization Technical
E2334Practice for Setting an Upper Confidence Bound For
Barriers to Trade (TBT) Committee.
aFractionorNumberofNon-Conformingitems,oraRate
of Occurrence for Non-conformities, Using Attribute
2. Referenced Documents
Data, When There is a Zero Response in the Sample
2.1 ASTM E11 Standards with Terms in This Standard:
E2489Practice for Statistical Analysis of One-Sample and
E29Practice for Using Significant Digits in Test Data to
Two-SampleInterlaboratoryProficiencyTestingPrograms
Determine Conformance with Specifications
E2554Practice for Estimating and Monitoring the Uncer-
E105Practice for Probability Sampling of Materials
tainty of Test Results of a Test Method Using Control
E122PracticeforCalculatingSampleSizetoEstimate,With
Chart Techniques
Specified Precision, the Average for a Characteristic of a
E2555Practice for Factors and Procedures forApplying the
Lot or Process
MIL-STD-105 Plans in Life and Reliability Inspection
E141Practice for Acceptance of Evidence Based on the
E2586Practice for Calculating and Using Basic Statistics
E2587Practice for Use of Control Charts in Statistical
1 Process Control
ThisterminologyisunderthejurisdictionofASTMCommitteeE11onQuality
and Statistics and is the direct responsibility of Subcommittee E11.70 on Editorial/
E2655Guide for Reporting Uncertainty of Test Results and
Terminology.
Use of the Term Measurement Uncertainty inASTM Test
Current edition approved Oct. 1, 2017. Published October 2017. Originally
ɛ4
Methods
approved in 1972. Last previous edition approved in 2013 as E456–13a . DOI:
10.1520/E0456-13AR17E02.
E2696Practice for Life and ReliabilityTesting Based on the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Exponential Distribution
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
E2709Practice for Demonstrating Capability to Comply
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. with an Acceptance Procedure
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´2
E456 − 13a (2017)
E2762Practice for Sampling a Stream of Product by Vari- average outgoing quality (AOQ), n—the average percent
ables Indexed by AQL defective of outgoing product including all accepted lots or
E2782Guide for Measurement Systems Analysis (MSA) batches, after any defective units found in them are replaced
E2819Practice for Single- and Multi-Level Continuous by acceptable units, plus all lots or batches which are not
SamplingofaStreamofProductbyAttributesIndexedby accepted after such lots or batches have been effectively
AQL 100% inspected and all defective units replaced by accept-
E2935 Practice for Conducting Equivalence Testing in able units. E1994
Laboratory Applications
average outgoing quality limit (AOQL), n—themaximumof
E3080Practice for Regression Analysis
theAOQsforallpossibleincomingpercentagesdefectivefor
2.2 ISO Standards:
the process, for a given acceptance sampling plan. E1994
ISO3534Statistics—Vocabulary and Symbols
average quality protection, n—a type of protection in which
Part2Applied Statistics
there is prescribed some chosen value of average percent
defective in the product after inspection (average outgoing
3. Terminology
quality limit (AOQL), that shall not be exceeded in the long
acceptance quality limit (AQL), n—quality limit that is the
run no matter what may be the level of percent defective in
worst tolerable process average when a continuing series of
the product submitted to the inspector. E1994
lots is submitted for acceptance sampling. E2234
average run length (ARL), n—the average number of times
accepted reference value, n—a value that serves as an
that a process will have been sampled and evaluated before
agreed-upon reference for comparison, and which is derived
a shift in process level is signaled. E2587
as: (1) a theoretical or established value, based on scientific
balanced incomplete block design (BIB), n—an incomplete
principles, (2) an assigned or certified value, based on
block design in which each block contains the same number
experimental work of some national or international
k of different versions from the t versions of a single
organization, or (3) a consensus or certified value, based on
principal factor arranged so that every pair of versions
collaborative experimental work under the auspices of a
occurs together in the same number, λ, of blocks from the b
scientific or engineering group. E177
blocks. E1325
accuracy, n—the closeness of agreement between a test result
bias, n—the difference between the expectation of the test
and an accepted reference value. E177
results and an accepted reference value. E177
aliases, n—in a fractional factorial design,twoormoreeffects
binary scale, n—nominal scale with only two possible
which are estimated by the same contrast and which,
categories. E2282
therefore, cannot be estimated separately. E1325
block factor, n—a factor that indexes division of experimental
area sampling,n—probabilitysamplinginwhichamap,rather
units into disjoint subsets. E1325
than a tabulation of sampling units, serves as the sampling
frame. E1402
bulk sampling, n—sampling to prepare a portion of a mass of
material that is representative of the whole. E1402
assignable cause, n—factor that contributes to variation in a
process or product output that is feasible to detect and
c chart, n—control chart that monitors the count of occur-
identify (see special cause). E2587
rences of an event in a defined increment of time or space.
E2587
attributes data,n—observedvaluesortestresultsthatindicate
the presence or absence of specific characteristics or counts
calibration, n—process of establishing a relationship between
of occurrences of events in time or space. E2587
a measurement device and a known standard value(s).
E2782
attributes, method of, n—measurement of quality by the
method of attributes consists of noting the presence (or
center line, n—line on a control chart depicting the average
absence) of some characteristic or attribute in each of the
level of the statistic being monitored. E2587
units in the group under consideration, and counting how
chance cause, n—source of inherent random variation in a
many units do (or do not) possess the quality attribute, or
process which is predictable within statistical limits (see
how many such events occur in the unit, group, or area.
common cause). E2587
E2334
characteristic, n—a property of items in a sample or popula-
audit subsample, n—a small subsample of a sample selected
tion which, when measured, counted or otherwise observed,
for review of all sample selection and data collection
helps to distinguish among the items. E2282
procedures. E141
check sample, n—see control sample. E2554
classification of defects, n—the enumeration of possible de-
Available from International Organization for Standardization (ISO), ISO
fects of the unit of product arranged according to their
Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier,
Geneva, Switzerland, http://www.iso.org. seriousness, that is, critical, major, or minor defect. E2234
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E456 − 13a (2017)
cluster sampling, n—sampling in which the sampling unit consumer’s risk, n—probability that a lot having specified
consistsofagroupofsubunits,allofwhicharemeasuredfor rejectable quality level will be accepted under a defined
sampled clusters. E1402 sampling plan. E2555
coefficient of determination, r , n—square of the correlation continuous sampling inspection, n—a method of sampling a
streamofproductinorderofproductionwherethesampling
coefficient. E3080
frequency is adjusted based on ongoing inspection results.
coefficient of variation (CV), n—for a nonnegative
E2819
characteristic,theratioofthestandarddeviationtothemean
contrast,n—alinearfunctionoftheobservationsforwhichthe
for a population or sample. E2586
sum of the coefficients is zero. E1325
collaborative study, n—interlaboratory study in which each
contrast analysis, n—a technique for estimating the param-
laboratory uses the defined method of analysis to analyze
eters of a model and making hypothesis tests on preselected
identical portions of homogeneous materials to assess the
linear combinations of the treatments (contrasts). E1325
performance characteristics obtained for that method of
analysis. E2489
control chart, n—chart on which are plotted a statistical
measure of a subgroup versus time of sampling along with
collaborative trial, n—see collaborative study. E2489
limits based on the statistical distribution of that measure so
common cause, n—see chance cause. E2587
astoindicatehowmuchcommon,orchance,causevariation
is inherent in the process or product. E2587
completely randomized design, n—a design in which the
treatments are assigned at random to the full set of experi-
control chart factor, n—a tabulated constant, depending on
mental units. E1325
samplesize,usedtoconvertspecifiedstatisticsorparameters
into a central line value or control limit appropriate to the
completely randomized factorial design, n—a factorial ex-
control chart. E2587
periment (including all replications) run in a completely
randomized design. E1325
control limits, n—limits on a control chart that are used as
criteria for signaling the need for action or judging whether
component of variance,n—apartofatotalvarianceidentified
a set of data does or does not indicate a state of statistical
with a specified source of variability. E1488
control based on a prescribed degree of risk. E2587
composite design, n—a design developed specifically for
control sample, n—sample taken from a stable, homogeneous
fitting second order response surfaces to study curvature,
material for the purposes of monitoring the performance of
constructed by adding further selected treatments to those
n a test method in a laboratory. E2554
obtained from a 2 factorial (or its fraction). E1325
critical defect, n—a defect that judgment and experience
confidence bound, n—see confidence limit. E2586
indicate would result in hazardous or unsafe conditions for
confidence coefficient, n—see confidence level. E2586
individuals using, maintaining, or depending upon the
product, or a defect that judgment and experience indicate is
confidence interval, n—an interval estimate [L, U] with the
likely to prevent performance of the function of a major end
statistics L and U as limits for the parameter θ and with
item. E2234
confidence level 1-α, where Pr(L≤θ≤U)≥1-α. E2586
defect, n—any nonconformance of the unit of product with
confidence level, n—the value, 1-α, of the probability associ-
specified requirements. E2234
ated with a confidence interval, often expressed as a
percentage. E2586
degrees of freedom,n—thenumberofindependentdatapoints
minus the number of parameters that have to be estimated
confidence limit, n—each of the limits, L and U, of a
before calculating the variance. E2586
confidence interval, or the limit of a one-sided confidence
interval. E2586
design of experiments, n—the arrangement in which an
experimental program is to be conducted, and the selection
confounded factorial design, n—a factorial experiment in
of the levels (versions) of one or more factors or factor
which only a fraction of the treatment combinations are run
combinations to be included in the experiment. Synonyms
in each block and where the selection of the treatment
include experiment design and experimental design. E1325
combinations assigned to each block is arranged so that one
ormoreprescribedeffectsis(are)confoundedwiththeblock double sampling plan, n—a multiple sampling plan in which
effect(s), while the other effects remain free from
up to two samplings can be taken and evaluated to accept or
confounding. E1325 reject a lot. E2234
confounding, n—combining indistinguishably the main effect equal complete coverage result, n—the numerical character-
of a factor or a differential effect between factors (interac- istic of interest calculated from observations made by
tions) with the effect of other factor(s), block factor(s) or drawing randomly from the frame, all of the sampling units
interactions(s). E1325 covered by the frame. E141
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E456 − 13a (2017)
equivalence, n—condition that two popul
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
´2 ´2
Designation: E456 − 13a (Reapproved 2017) E456 − 13a (Reapproved 2017)An American National Standard
Standard Terminology
Relating to Quality and Statistics
This standard is issued under the fixed designation E456; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
ε NOTE—Reapproved with new terms added and other terms corrected editorially in October 2017.
ε NOTE—New terms were added and other terms were corrected editorially in April 2018.
1. Scope
1.1 This standard is the general terminology standard for terms defined in the standards of Committee E11 on Quality and
Statistics.
1.2 A term in this standard which lists an attribution to an E11 technical standard indicates that the standard is normative for
that term. Any changes in the term definition in the normative standard will be editorially changed in this standard. Any terms
added to an E11 standard will be editorially added to this standard with an attribution to that standard.
1.3 Term definitions that are similar to ISO 3534 will be noted in this standard, but ISO 3534 will not be considered normative
for any E11 terms.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM E11 Standards with Terms in This Standard:
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
E105 Practice for Probability Sampling of Materials
E122 Practice for Calculating Sample Size to Estimate, With Specified Precision, the Average for a Characteristic of a Lot or
Process
E141 Practice for Acceptance of Evidence Based on the Results of Probability Sampling
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E178 Practice for Dealing With Outlying Observations
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E1169 Practice for Conducting Ruggedness Tests
E1325 Terminology Relating to Design of Experiments
E1402 Guide for Sampling Design
E1488 Guide for Statistical Procedures to Use in Developing and Applying Test Methods
E1994 Practice for Use of Process Oriented AOQL and LTPD Sampling Plans
E2234 Practice for Sampling a Stream of Product by Attributes Indexed by AQL
E2281 Practice for Process Capability and Performance Measurement
E2282 Guide for Defining the Test Result of a Test Method
E2334 Practice for Setting an Upper Confidence Bound For a Fraction or Number of Non-Conforming items, or a Rate of
Occurrence for Non-conformities, Using Attribute Data, When There is a Zero Response in the Sample
E2489 Practice for Statistical Analysis of One-Sample and Two-Sample Interlaboratory Proficiency Testing Programs
E2554 Practice for Estimating and Monitoring the Uncertainty of Test Results of a Test Method Using Control Chart Techniques
This terminology is under the jurisdiction of ASTM Committee E11 on Quality and Statistics and is the direct responsibility of Subcommittee E11.70 on
Editorial/Terminology.
ɛ4
Current edition approved Oct. 1, 2017. Published October 2017. Originally approved in 1972. Last previous edition approved in 2013 as E456 – 13a . DOI:
10.1520/E0456-13AR17E01.10.1520/E0456-13AR17E02.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´2
E456 − 13a (2017)
E2555 Practice for Factors and Procedures for Applying the MIL-STD-105 Plans in Life and Reliability Inspection
E2586 Practice for Calculating and Using Basic Statistics
E2587 Practice for Use of Control Charts in Statistical Process Control
E2655 Guide for Reporting Uncertainty of Test Results and Use of the Term Measurement Uncertainty in ASTM Test Methods
E2696 Practice for Life and Reliability Testing Based on the Exponential Distribution
E2709 Practice for Demonstrating Capability to Comply with an Acceptance Procedure
E2762 Practice for Sampling a Stream of Product by Variables Indexed by AQL
E2782 Guide for Measurement Systems Analysis (MSA)
E2819 Practice for Single- and Multi-Level Continuous Sampling of a Stream of Product by Attributes Indexed by AQL
E2935 Practice for Conducting Equivalence Testing in Laboratory Applications
E3080 Practice for Regression Analysis
2.2 ISO Standards:
ISO 3534 Statistics—Vocabulary and Symbols
Part 2 Applied Statistics
3. Terminology
acceptance quality limit (AQL), n—quality limit that is the worst tolerable process average when a continuing series of lots is
submitted for acceptance sampling. E2234
accepted reference value, n—a value that serves as an agreed-upon reference for comparison, and which is derived as: (1) a
theoretical or established value, based on scientific principles, (2) an assigned or certified value, based on experimental work
of some national or international organization, or (3) a consensus or certified value, based on collaborative experimental work
under the auspices of a scientific or engineering group. E177
accuracy, n—the closeness of agreement between a test result and an accepted reference value. E177
aliases, n—in a fractional factorial design, two or more effects which are estimated by the same contrast and which, therefore,
cannot be estimated separately. E1325
area sampling, n—probability sampling in which a map, rather than a tabulation of sampling units, serves as the sampling frame.
E1402
assignable cause, n—factor that contributes to variation in a process or product output that is feasible to detect and identify (see
special cause). E2587
attributes data, n—observed values or test results that indicate the presence or absence of specific characteristics or counts of
occurrences of events in time or space. E2587
attributes, method of, n—measurement of quality by the method of attributes consists of noting the presence (or absence) of some
characteristic or attribute in each of the units in the group under consideration, and counting how many units do (or do not)
possess the quality attribute, or how many such events occur in the unit, group, or area. E2334
audit subsample, n—a small subsample of a sample selected for review of all sample selection and data collection procedures.
E141
average outgoing quality (AOQ), n—the average percent defective of outgoing product including all accepted lots or batches,
after any defective units found in them are replaced by acceptable units, plus all lots or batches which are not accepted after such
lots or batches have been effectively 100 % inspected and all defective units replaced by acceptable units. E1994
average outgoing quality limit (AOQL), n—the maximum of the AOQs for all possible incoming percentages defective for the
process, for a given acceptance sampling plan. E1994
average quality protection, n—a type of protection in which there is prescribed some chosen value of average percent defective
in the product after inspection (average outgoing quality limit (AOQL), that shall not be exceeded in the long run no matter what
may be the level of percent defective in the product submitted to the inspector. E1994
average run length (ARL), n—the average number of times that a process will have been sampled and evaluated before a shift
in process level is signaled. E2587
balanced incomplete block design (BIB), n—an incomplete block design in which each block contains the same number k of
different versions from the t versions of a single principal factor arranged so that every pair of versions occurs together in the
same number, λ, of blocks from the b blocks. E1325
Available from International Organization for Standardization (ISO), ISO Central Secretariat, BIBC II, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva,
Switzerland, http://www.iso.org.
´2
E456 − 13a (2017)
bias, n—the difference between the expectation of the test results and an accepted reference value. E177
binary scale, n—nominal scale with only two possible categories. E2282
block factor, n—a factor that indexes division of experimental units into disjoint subsets. E1325
bulk sampling, n—sampling to prepare a portion of a mass of material that is representative of the whole. E1402
c chart, n—control chart that monitors the count of occurrences of an event in a defined increment of time or space. E2587
calibration, n—process of establishing a relationship between a measurement device and a known standard value(s). E2782
center line, n—line on a control chart depicting the average level of the statistic being monitored. E2587
chance cause, n—source of inherent random variation in a process which is predictable within statistical limits (see common
cause). E2587
characteristic, n—a property of items in a sample or population which, when measured, counted or otherwise observed, helps to
distinguish among the items. E2282
check sample, n—see control sample. E2554
classification of defects, n—the enumeration of possible defects of the unit of product arranged according to their seriousness, that
is, critical, major, or minor defect. E2234
cluster sampling, n—sampling in which the sampling unit consists of a group of subunits, all of which are measured for sampled
clusters. E1402
coefficient of determination, r , n—square of the correlation coefficient, r.coefficient. E3080
coefficient of variation (CV), n—for a nonnegative characteristic, the ratio of the standard deviation to the mean for a population
or sample. E2586
collaborative study, n—interlaboratory study in which each laboratory uses the defined method of analysis to analyze identical
portions of homogeneous materials to assess the performance characteristics obtained for that method of analysis. E2489
collaborative trial, n—see collaborative study. E2489
common cause, n—see chance cause. E2587
completely randomized design, n—a design in which the treatments are assigned at random to the full set of experimental units.
E1325
completely randomized factorial design, n—a factorial experiment (including all replications) run in a completely randomized
design. E1325
component of variance, n—a part of a total variance identified with a specified source of variability. E1488
composite design, n—a design developed specifically for fitting second order response surfaces to study curvature, constructed by
n
adding further selected treatments to those obtained from a 2 factorial (or its fraction). E1325
confidence bound, n—see confidence limit. E2586
confidence coefficient, n—see confidence level. E2586
confidence interval, n—an interval estimate [L, U] with the statistics L and U as limits for the parameter θ and with confidence
level 1-α, where Pr(L ≤ θ ≤ U) ≥ 1-α. E2586
confidence level, n—the value, 1-α, of the probability associated with a confidence interval, often expressed as a percentage.
E2586
confidence limit, n—each of the limits, L and U, of a confidence interval, or the limit of a one-sided confidence interval. E2586
confounded factorial design, n—a factorial experiment in which only a fraction of the treatment combinations are run in each
block and where the selection of the treatment combinations assigned to each block is arranged so that one or more prescribed
effects is (are) confounded with the block effect(s), while the other effects remain free from confounding. E1325
confounding, n—combining indistinguishably the main effect of a factor or a differential effect between factors (interactions) with
the effect of other factor(s), block factor(s) or interactions(s). E1325
consumer’s risk, n—probability that a lot having specified rejectable quality level will be accepted under a defined sampling plan.
E2555
´2
E456 − 13a (2017)
continuous sampling inspection, n—a method of sampling a stream of product in order of production where the sampling
frequency is adjusted based on ongoing inspection results. E2819
contrast, n—a linear function of the observations for which the sum of the coefficients is zero. E1325
contrast analysis, n—a technique for estimating the parameters of a model and making hypothesis tests on preselected linear
combinations of the treatments (contrasts). E1325
control chart, n—chart on which are plotted a statistical measure of a subgroup versus time of sampling along with limits based
on the statistical distribution of that measure so as to indicate how much common, or chance, cause variation is inherent in the
process or product. E2587
control chart factor, n—a tabulated constant, depending on sample size, used to convert specified statistics or parameters into a
central line value or control limit appropriate to the control chart. E2587
control limits, n—limits on a control chart that are used as criteria for signaling the need for action or judging whether a set of
data does or does not indicate a state of statistical control based on a prescribed degree of risk. E2587
control sample, n—sample taken from a stable, homogeneous material for the purposes of monitoring the performance of a test
method in a laboratory. E2554
correlation coeffecient, n—for a population, ρ, a dimensionless measure of association between two variables X and Y, equal to
the covariance divided by the product of σ and times σ . E3080
X Y
correlation coeffecient, n—for a sample, r, the estimate of the parameter ρ from the data. E3080
covariance, n—of a population, cov(X, Y), for two variables, X and Y, the expected value of (X – μ )(Y – μ ). E3080
X Y
covariance, n—of a sample, the estimate of the parameter cov(X, Y) from the data. E3080
critical defect, n—a defect that judgment and experience indicate would result in hazardous or unsafe conditions for individuals
using, maintaining, or depending upon the product, or
...
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