ISO 5725-1:2023 測定方法と結果の精度（真偽と精度） — Part 1: 一般原則と定義 | ページ 6

3.1

test result

value of a characteristic obtained by carrying out a specified test method

Note 1 to entry: The test method should specify that one or a number of individual observations be made, and their average or another appropriate function (such as the median or the standard deviation) be reported as the test result. It can also require standard corrections to be applied, such as correction of gas volumes to standard temperature and pressure. Thus a test result can be a result calculated from several observed values. In the simple case, the test result is the observed value itself.

Note 2 to entry: When measurement is used (for methods or results) in this document it means test or measurement (for methods or results).

[SOURCE:ISO 3534-2:2006, 3.4.1, modified — Note 2 to entry rephrased.]

3.2

accepted reference value

[SOURCE:ISO 3534-2:2006, 3.2.7]

3.3

level

<test item> general average of the test results (3.1) or test results (3.1) from all laboratories for one particular test item or test item tested

Note 1 to entry: The accuracy of a measurement method is defined at each level and can be different.

3.4

measurement

test item

sample which is prepared and can be presumed to be identical for the intended purpose

Note 1 to entry: Practical requirements are stated in the protocol of the intended purpose.

Note 2 to entry: Examples of test items: sample, product, artifact, reference test item, equipment, measurement standard.

3.5

accuracy

closeness of agreement between a test result (3.1) and the true value

Note 1 to entry: In practice, the accepted reference value is substituted for the true value.

Note 2 to entry: The term accuracy, when applied to a set of test results, involves a combination of random components and a common systematic error or bias component.

Note 3 to entry: Accuracy refers to a combination of trueness and precision.

Note 4 to entry: Common systematic error is called bias component.

[SOURCE:ISO 3534-2:2006, 3.3.1, modified — Note 4 to entry added.]

3.6

trueness

closeness of agreement between the expectation of test results (3.1) and a true value

Note 1 to entry: The measure of trueness is usually expressed in terms of bias.

Note 2 to entry: Trueness is sometimes referred to as “accuracy of the mean”. This usage is not recommended.

Note 3 to entry: In practice, the accepted reference value is substituted for the true value.

[SOURCE:ISO 3534-2:2006, 3.3.3]

3.7

outlier

value from a set of values which is inconsistent with the other values of that set, identified by a statistical test

Note 1 to entry: ISO 5725-2 specifies the statistical tests and the significance level (3.3) to be used to identify outliers in trueness and precision experiments.

3.8

bias

difference between the expectation of the test results (3.1) and a true value

Note 1 to entry: Bias is the total systematic error as contrasted to random error. There can be one or more systematic error components contributing to the bias. A larger systematic difference from the accepted reference value is reflected by a larger bias value.

Note 2 to entry: The bias of a measuring instrument is normally estimated by averaging the error of indication over an appropriate number of repeated measurements. The error of indication is the ‘’indication of a measuring instrument minus a true value of corresponding input quantity’’.

Note 3 to entry: In practice, the accepted reference value is substituted for the true value.

[SOURCE:ISO 3534-2:2006, 3.3.2]

3.9

bias of the measurement method

difference between the expectation of test results (3.1) obtained from all laboratories using the same method on identical test or measurement items and an accepted reference value (3.2)

Note 1 to entry: In practice, the bias of the measurement method is measured by the displacement of the average of results from a large number of different laboratories all using the same method. The bias of a measurement method can be different at different levels (3.3) .

3.10

laboratory bias

difference between the expectation of the test results (3.1) obtained from a particular laboratory and an accepted reference value (3.2) under the conditions of a particular experiment

Note 1 to entry: It is assessed based on the performance of a particular laboratory.

3.11

laboratory component of bias B

difference between the laboratory bias (3.10) and the bias of the measurement method (3.9)

Note 1 to entry: The laboratory component of bias is specific to a given laboratory and the conditions of measurement within the laboratory, and also it can be different at different levels of the measurement method.

Note 2 to entry: The laboratory component of bias is relative to the overall average result, not the true or accepted reference value.

Note 3 to entry: Laboratory component of bias can be named effect of laboratory.

Note 4 to entry: The relationship between the laboratory bias, Δ, the bias of the measurement method, δ, and the laboratory component of the bias B is detailed in ISO 5725-4.

3.12

precision

closeness of agreement between independent test results (3.1) obtained under stipulated conditions

Note 1 to entry: Precision depends only on the distribution of random errors and does not relate to the true value or the specified value.

Note 2 to entry: The measure of precision is usually expressed in terms of imprecision and computed as a standard deviation of the test results. Less precision is reflected by a larger standard deviation.

Note 3 to entry: Quantitative measures of precision depend critically on the stipulated conditions. Repeatability and reproducibility conditions are particular sets of extreme conditions.

[SOURCE:ISO 3534-2:2006, 3.3.4]

3.13

repeatability

precision under repeatability conditions (3.14)

Note 1 to entry: Repeatability can be expressed quantitatively in terms of the dispersion characteristics of the results.

[SOURCE:ISO 3534-2:2006, 3.3.5]

3.14

repeatability conditions

observation conditions where independent test results (3.1) are obtained with the same method on identical test or measurement items in the same test or measuring facility by the same operator using the same equipment within short intervals of time

[SOURCE:ISO 3534-2:2006, 3.3.6]

3.15

repeatability standard deviation

standard deviation of test results (3.1) obtained under repeatability conditions (3.14)

Note 1 to entry: It is a measure of dispersion of the distribution of test results under repeatability conditions.

Note 2 to entry: Similarly"repeatability variance” and “repeatability coefficient of variation” can be defined and used as measures of the dispersion of test results under repeatability conditions.

Note 3 to entry: Coefficient of variation should be used with caution. Variance or standard deviation is preferred.

[SOURCE:ISO 3534-2:2006, 3.3.7, modified — Note 3 to entry added.]

3.16

repeatability critical difference

value less than or equal to which the absolute difference between two final values, each of them representing a series of test results (3.1) obtained under repeatability (3.13) , is expected to be with a specified probability

Note 1 to entry: Examples of final results are the mean and the median of the series of results; the series itself can consist of only one result.

[SOURCE:ISO 3534-2:2006, 3.3.8]

3.17

repeatability limit

r

repeatability critical difference (3.16) for a specified probability of 95 %

[SOURCE:ISO 3534-2:2006, 3.3.9]

3.18

reproducibility

precision under reproducibility conditions (3.19)

Note 1 to entry: Reproducibility can be expressed quantitatively in terms of the dispersion characteristics of the results.

Note 2 to entry: Results are usually understood to be corrected results.

[SOURCE:ISO 3534-2:2006, 3.3.10]

3.19

reproducibility conditions

observation conditions where independent test results (3.1) are obtained with the same method on identical test or measurement items in different test or measurement facilities with different operators using different equipment

[SOURCE:ISO 3534-2:2006, 3.3.11]

3.20

reproducibility standard deviation

standard deviation of test results (3.1) obtained under reproducibility conditions (3.19)

Note 1 to entry: It is a measure of the dispersion of the distribution of test results under reproducibility conditions.

Note 2 to entry: Similarly a"reproducibility variance” and"reproducibility coefficient of variation” can be defined and used as measures of the dispersion of test results under reproducibility conditions.

[SOURCE:ISO 3534-2:2006, 3.3.12]

3.21

reproducibility critical difference

value less than or equal to which the absolute difference between two final values, each of them representing a series of test results (3.1) obtained under reproducibility conditions (3.19) , is expected to be with a specified probability

Note 1 to entry: Instances of final results are the mean and the median of the series of test results, the series itself can consist of only one test result.

[SOURCE:ISO 3534-2:2006, 3.3.13]

3.22

reproducibility limit

R

reproducibility critical difference (3.21) for a specified probability of 95 %

[SOURCE:ISO 3534-2:2006, 3.3.14]

3.23

intermediate precision

precision under intermediate precision conditions

[SOURCE:ISO 3534-2:2006, 3.3.15]

3.24

intermediate precision conditions

conditions where test results (3.1) are obtained with the same method, on identical test or measurement items in the same test or measurement facility, under some different operating condition

Note 1 to entry: There are four elements to the operating condition: time, calibration, operator and equipment;

Note 2 to entry: A test house is an example of a test facility. A metrology laboratory is an example of a measurement facility;

Note 3 to entry: In addition to the four elements of the operating condition listed above, some more elements may be different as batch, preparation and others.

Note 4 to entry: The above conditions can change independently.

[SOURCE:ISO 3534-2:2006, 3.3.16, modified —Notes 3 and 4 to entry added.]

3.25

intermediate precision standard deviation

standard deviation of test results (3.1) obtained under intermediate precision conditions (3.24)

[SOURCE:ISO 3534-2:2006, 3.3.17]

3.26

intermediate precision critical difference

value less than or equal to which the absolute difference between two final values, each of them representing a series of test results (3.1) obtained under intermediate precisions conditions (3.24) , is expected to be with a specified probability

[SOURCE:ISO 3534-2:2006, 3.3.18]

3.27

intermediate precision limit

intermediate precision critical difference (3.26) for a specified probability of 95 %

[SOURCE:ISO 3534-2:2006, 3.3.19]