ISO 2602-1980 PDF

Full title and description

ISO 2602:1980 — Statistical interpretation of test results — Estimation of the mean — Confidence interval. An International Standard that specifies the statistical treatment of test results required to estimate a confidence interval for the mean of a population when the population variance is unknown.

Abstract

Concerns the estimation of the mean of a normal population on the basis of a series of tests applied to a random sample drawn from that population when the population variance is unknown, and the calculation of the confidence interval for the population mean derived from the sample mean and sample standard deviation. The standard notes that the test method may be subject to systematic errors and provides the statistical approach to quantify interval uncertainty around the estimated mean.

General information

• Status: Published (confirmed following periodic review in 2021).
• Publication date: 1 February 1980 (published edition 1, 1980).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 03.120.30 (Application of statistical methods).
• Edition / version: Edition 1 (1980).
• Number of pages: 5 pages.

Scope

This standard applies to the statistical handling of test results needed to calculate a confidence interval for the population mean when sampling from a (approximately) normal distribution and the population variance is not known. It defines the assumptions, the statistical model and the practical use of sample statistics to produce interval estimates of the mean for test and measurement applications.

Key topics and requirements

• Estimation of the population mean from sample data drawn at random.
• Construction of confidence intervals for the mean when the population variance is unknown.
• Use of the sample mean and sample standard deviation as the basis for interval estimation (classical t-based approach under normality assumptions).
• Statement of assumptions (approximate normality of the population and random sampling) and note on possible systematic errors in test methods.
• Guidance on interpretation of the resulting confidence interval in the context of test-result reporting.

Typical use and users

Applied by laboratory statisticians, test method developers, quality engineers, metrologists and analysts who need a standardized method to report interval estimates of a population mean from test data. Typical uses include reporting uncertainty around averaged test results, comparing means between processes or batches, and documenting statistical treatment of test series in technical reports or standards-compliant test methods.

Related standards

Standards commonly used alongside or relevant to ISO 2602 include ISO 3534 (Statistics — vocabulary and symbols), the ISO 16269 series (statistical interpretation of data — various parts on estimation and intervals), the ISO 5725 series (accuracy — trueness and precision of measurement methods and results), ISO 13528 (statistical methods for proficiency testing), and international guidance on measurement uncertainty (for example JCGM/GUM documents). These related documents cover terminology, precision/trueness evaluation, broader interval and distribution treatments, and uncertainty reporting.

Keywords

confidence interval, mean estimation, sample mean, sample standard deviation, Student's t, normal distribution, statistical interpretation, test results, ISO/TC 69, measurement statistics

FAQ

Q: What is this standard?

A: ISO 2602:1980 is an ISO international standard that specifies how to estimate the mean of a population from sample test results and how to construct a confidence interval for that mean when the population variance is unknown.

Q: What does it cover?

A: It covers the statistical model, assumptions and practical procedure for deriving a confidence interval for a population mean from a random sample of test results, using the sample statistics available when population variance is not known.

Q: Who typically uses it?

A: Laboratory statisticians, quality engineers, test method authors, metrologists and anyone reporting averaged test results who needs a standardized approach to interval estimation of means.

Q: Is it current or superseded?

A: The 1980 edition remains the published edition. The publication was last reviewed and confirmed in 2021, so this edition is still current (last confirmation recorded in 2021).

Q: Is it part of a series?

A: ISO 2602 is a standalone standard addressing mean estimation and confidence intervals, but it sits within the wider body of ISO statistical standards (ISO/TC 69 deliverables) and is commonly used together with other ISO statistics standards such as ISO 3534, ISO 16269 series and the ISO 5725 series.

Q: What are the key keywords?

A: Confidence interval; estimation of the mean; sample standard deviation; t-distribution; normal population; statistical interpretation; test results.