NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PUBLICATIONS

Trapezoidal and Triangular Distributions for Type B Evaluation of Standard Uncertainty

Published

Author(s)

Raghu N. Kacker, James F. Lawrence

Abstract

A Type B standard uncertainty is determined from a probability distribution specified by scientific judgment based on all available information. The ISO-GUM discusses symmetric distributions only. Sometimes an asymmetric distribution is needed. We describe a trapezoidal distribution that may be asymmetric. Triangular and rectangular distributions are special cases of trapezoidal distribution. Then we discuss how a trapezoidal distribution may be used to determine an asymmetric correction for bias and its associated standard uncertainty.
Citation
Metrologia
Volume
44
Pub Type
Journals

Download Paper

Local Download

Keywords

ISO-GUM, measurement uncertainty, rectangular distribution uncertainty, variance components
Mathematics and statistics

Citation

Kacker, R. and Lawrence, J. (2007), Trapezoidal and Triangular Distributions for Type B Evaluation of Standard Uncertainty, Metrologia, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=50853 (Accessed October 18, 2025)

Issues

If you have any questions about this publication or are having problems accessing it, please contact [email protected].

Created February 26, 2007, Updated January 27, 2020
Was this page helpful?