Standard Withdrawn, No replacement   Last Updated: Dec 31, 2010 Track Document
ASTM D4853-97(2002)

Standard Guide for Reducing Test Variability (Withdrawn 2008)

Standard Guide for Reducing Test Variability (Withdrawn 2008) D4853-97R02 ASTM|D4853-97R02|en-US Standard Guide for Reducing Test Variability (Withdrawn 2008) Standard new BOS Vol. 07.02 Committee D13
$ 0.00 Out of stock

Significance and Use

This guide can be used at any point in the development or improvement of a test method, if it is desired to pursue reduction of its variability.

There are three circumstances in which a subcommittee responsible for a test method would want to reduce test variability:

4.2.1 During the development of a new test method, ruggedness testing might reveal factors which produce an unacceptable level of variability, but which can be satisfactorily controlled once the factors are identified.

4.2.2 Another is when analysis of data from an interlaboratory test of a test method shows significant differences between levels of factors or significant interactions which were not desired or expected. Such an occurrence is an indicator of lack of control which means that the precision of the test method is not predictable.

4.2.3 The third situation is when the method is in statistical control, but it is desired to improve its precision, perhaps because the precision is not good enough to detect practical differences with a reasonable number of specimens.

The techniques in this guide help to detect a statistical difference between test results. They do not directly answer questions about practical differences. A statistical difference is one which is not due to experimental error, that is, chance variation. Each statistical difference found by the use of this guide must be compared to a practical difference, the size of which is a matter of engineering judgment. For example, a change of one degree in temperature of water may show a statistically significant difference of 0.05 % in dimensional change, but 0.05 % may be of no importance in the use to which the test may be put.

Scope

1.1 This guide serves as an aid to subcommittees writing and maintaining test methods. It helps to (1) determine if it is possible to reduce test variability, and, if so, ( 2) provide a systematic approach to the reduction.

1.2 This guide includes the following topics:

Topic TitleSection Number
Scope1
Referenced Documents2
Definitions3
Significance and Use4
Measures of Test Variability5
Unnecessary Test Variability6
Identifying Probable Causes of Test Variability7
Determining the Causes of Test Variability8
Averaging9
Calibration10
Keywords11

1.3 The annexes include:

Topic TitleAnnex Number
Statistical Test SelectionAnnex A1
Frequency Distribution IdentificationAnnex A2
Design of Ruggedness TestsAnnex A3
Ruggedness Test Analysis:
Unknown or Undefined Distribution—Small SampleAnnex A4
Unknown or Undefined Distribution—Large SampleAnnex A5
Binomial DistributionAnnex A6
Poisson DistributionAnnex A7
Normal DistributionAnnex A8
Design of a Randomized Block ExperimentAnnex A9
Randomized Block Experiment Analysis:
Unknown or Undefined Distribution—Small SampleAnnex A10
Unknown or Undefined Distribution—Large SampleAnnex A11
Binomial DistributionAnnex A12
Poisson DistributionAnnex A13
Normal DistributionAnnex A14
Averaging:
No CompositingAnnex A15
CompositingAnnex A16
Language unavailable
Format unavailable
Related
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center