{domain:"www.qualitydigest.com",server:"169.47.211.87"} Skip to main content

User account menu
Main navigation
  • Topics
    • Customer Care
    • FDA Compliance
    • Healthcare
    • Innovation
    • Lean
    • Management
    • Metrology
    • Operations
    • Risk Management
    • Six Sigma
    • Standards
    • Statistics
    • Supply Chain
    • Sustainability
    • Training
  • Videos/Webinars
    • All videos
    • Product Demos
    • Webinars
  • Advertise
    • Advertise
    • Submit B2B Press Release
    • Write for us
  • Metrology Hub
  • Training
  • Subscribe
  • Log in
Mobile Menu
  • Home
  • Topics
    • 3D Metrology-CMSC
    • Customer Care
    • FDA Compliance
    • Healthcare
    • Innovation
    • Lean
    • Management
    • Metrology
    • Operations
    • Risk Management
    • Six Sigma
    • Standards
    • Statistics
    • Supply Chain
    • Sustainability
    • Training
  • Login / Subscribe
  • More...
    • All Features
    • All News
    • All Videos
    • Contact
    • Training

Inaccurate? Precisely!

On apples and aiming

Fred Mason
Wed, 08/09/2006 - 22:00
  • Comment
  • RSS

Social Sharing block

  • Print
Body
Many people know about William Tell shooting the apple on his son’s head. What can this archery event teach us about accuracy and precision? What do these words mean? When are they equal, and when are they not? “Accuracy,” “precision” and “resolution” are sometimes misunderstood or misrepresented. A measurement can be precise yet inaccurate, regardless of its resolution. And the resolution of a measurement may have nothing to do with how many places there are after the decimal point. How can that be?

ISO standards and most of the standards labs around the world—NIST, the National Physical Laboratory, Physikalisch-Technische Bundesanstalt, etc. —provide definitions of these important words, and there are many contextual definitions that are specific to devices or situations. I’m not going to accurately match any of those definitions. I’ll just explain them as concepts with application examples.

First, it’s important to understand the differences in these words. Many people use them interchangeably, as if they have the same meaning. They don’t. Even if you know the definitions, there may be more to them than meets the eye. Let’s start with the definition of "accuracy."

 …

Want to continue?
Log in or create a FREE account.
Enter your username or email address
Enter the password that accompanies your username.
By logging in you agree to receive communication from Quality Digest. Privacy Policy.
Create a FREE account
Forgot My Password

Add new comment

Image CAPTCHA
Enter the characters shown in the image.
Please login to comment.
      

© 2025 Quality Digest. Copyright on content held by Quality Digest or by individual authors. Contact Quality Digest for reprint information.
“Quality Digest" is a trademark owned by Quality Circle Institute Inc.

footer
  • Home
  • Print QD: 1995-2008
  • Print QD: 2008-2009
  • Videos
  • Privacy Policy
  • Write for us
footer second menu
  • Subscribe to Quality Digest
  • About Us
  • Contact Us