--- title: The CTO's Corner: Repeatability and Reproducibility description: Did you know you can perform cluster analysis using Statgraphics? Join us for the latest webinar and let Dr. Neil Polhemus demonstrate the capabilities we have to offer! image: https://www.statgraphics.com/hubfs/R%26R%20plot%20for%20measurement.png --- [![stat19plain-01-1](https://www.statgraphics.com/hs-fs/hubfs/stat19plain-01-1.png?width=2324&name=stat19plain-01-1.png "stat19plain-01-1")](https://www.statgraphics.com) - [Products](https://www.statgraphics.com/product) - [Learn](https://www.statgraphics.com/statistics-library) - [Training](https://www.statgraphics.com/training-and-consulting) - [Product](https://www.statgraphics.com/product) - [Centurion XVIII](https://www.statgraphics.com/centurion-xvii) - [Sigma Express](https://www.statgraphics.com/statgraphics-sigma-express) - [Online](https://www.statgraphics.com/statgraphics-stratus) - [Web Services](https://www.statgraphics.com/statgraphics-web-services) - [Learn](https://www.statgraphics.com/statistics-library) - [Statistics Library](https://www.statgraphics.com/statistics-library) - [Six Sigma & Lean](https://www.statgraphics.com/six-sigma-lean) - [Instructional Videos](https://www.statgraphics.com/instructional-videos) - [Applications/ Case Studies](https://www.statgraphics.com/application) - [Training & Consulting](https://www.statgraphics.com/training-and-consulting) - [Statpoint Seminars](https://www.statgraphics.com/statpoint-seminar) - [Statpoint Instructors](https://www.statgraphics.com/statpoint-instructor) - [Training Partners](https://www.statgraphics.com/training-partners) - [Webinars](https://www.statgraphics.com/webinars) - [Support](https://www.statgraphics.com/customer-support-overview) - [Blog](https://www.statgraphics.com/blog) - [Store](http://store.statgraphics.com) ### Statgraphics ## [Centurion](https://www.statgraphics.com/centurion-overview) #### [LEARN MORE](https://www.statgraphics.com/centurion-overview) ### Statgraphics ## [Sigma *express*](https://www.statgraphics.com/statgraphics-sigma-express) #### [LEARN MORE](https://www.statgraphics.com/statgraphics-sigma-express) ### Statgraphics ## [*Stratus*](https://www.statgraphics.com/statgraphics-stratus) #### [LEARN MORE](https://www.statgraphics.com/statgraphics-stratus) ### Statgraphics ## [Web Services](https://www.statgraphics.com/statgraphics-web-services) #### [LEARN MORE](https://www.statgraphics.com/statgraphics-web-services) ## [Statistics Library](https://www.statgraphics.com/statistics-library) #### [LEARN MORE](https://www.statgraphics.com/statistics-library) ## [Six Sigma & Lean](https://www.statgraphics.com/six-sigma-lean) #### [LEARN MORE](https://www.statgraphics.com/six-sigma-lean) ## [Instructional Videos](https://www.statgraphics.com/instructional-videos) #### [LEARN MORE](https://www.statgraphics.com/instructional-videos) ## [Applications/ Case Studies](https://www.statgraphics.com/statistical-applications) #### [LEARN MORE](https://www.statgraphics.com/statistical-applications) ## [Statgraphics Seminars](https://www.statgraphics.com/statpoint-seminar) #### [LEARN MORE](https://www.statgraphics.com/statpoint-seminar) ## [Statgraphics Instructors](https://www.statgraphics.com/statpoint-instructor) #### [LEARN MORE](https://www.statgraphics.com/statpoint-instructor) ## [Training Partners](https://www.statgraphics.com/public-seminar) #### [LEARN MORE](https://www.statgraphics.com/public-seminar) ## [Webinars](https://www.statgraphics.com/webinars) #### [LEARN MORE](https://www.statgraphics.com/webinars) ![bloglogo3-01](https://www.statgraphics.com/hs-fs/hubfs/bloglogo3-01.png?width=400&height=101&name=bloglogo3-01.png "bloglogo3-01") Apr 5, 2017, 2:43:34 PM ## [The CTO's Corner: Repeatability and Reproducibility](https://www.statgraphics.com/blog/ctos_corner_gage_rr) ![](https://www.statgraphics.com/hs-fs/file-2017572828-jpg/website-assets/neil-polhemus.jpg?width=50&name=neil-polhemus.jpg) By: [Dr. Neil Polhemus](https://www.statgraphics.com/blog/author/dr-neil-polhemus) Published under: [Data analytics](https://www.statgraphics.com/blog/topic/data-analytics), [Gage R&R](https://www.statgraphics.com/blog/topic/gage-rr), [Gage Studies](https://www.statgraphics.com/blog/topic/gage-studies), [repeatability](https://www.statgraphics.com/blog/topic/repeatability), [Reproducibility](https://www.statgraphics.com/blog/topic/reproducibility) **Repeatability and Reproducibility: Are your measurements precise enough to analyze?** The rapidly exploding interest in predictive analytics has increased dramatically the number of people applying statistical techniques to their data. Too often, analysts take whatever data they can find, enter it into a statistical package, run a procedure or two, and go directly to the final results. They fail to realize that all data is subject to some amount of measurement error. Unless the analyst has a good handle on how large that error is, it is hard to judge the reliability and applicability of the final results. Prior to the use of any statistical procedure, it is important to understand how repeatable and reproducible the individual data values are. By repeatable, we mean the potential difference between the results at hand and the results that might be obtained if we repeated our study under similar conditions. By reproducible, we mean the potential difference between the results that we obtained and the results that someone else might get if they tried to reproduce our study. ![R&R plot for measurement.png](https://www.statgraphics.com/hs-fs/hubfs/R%26R%20plot%20for%20measurement.png?width=641&height=401&name=R%26R%20plot%20for%20measurement.png) The [*measurement systems analysis and Gage Studies*](https://www.statgraphics.com/measurement-systems-analysis) section of Statgraphics Centurion contains 8 procedures designed to help estimate Repeatability and Reproducibility (R&R). 5 of those procedures deal with variable data (measurements) while the other 3 deal with attribute data. In the variable studies, multiple appraisers make repeated measurements on identical samples (or close to identical samples if testing is destructive). In attribute studies, multiple appraisers repeatedly rate selected items. Statistics calculated from such studies, such as the *Precision/Tolerance* *Ratio*, the *Percent of Total Variation,* the *Number of Distinct Categories,* and *Cohen’s Kappa Measure of Interrater Agreement*  let the analyst know whether their measurement system is good enough to expect usable results from other analyses. Note: if your data come from a destructive test that can’t be repeated, check out [*How to Perform a Repeatability and Reproducibility Study for Destructive Tests Using STATGRAPHICS*](https://www.statgraphics.com/hubfs/PDFs/How_To_Perform_a_Repeatability_and_Reproducibility_Study_for_Destructive_Tests.pdf?t=1491253384528) at [http://www.statgraphics.com/how-to-guides](https://www.statgraphics.com/how-to-guides) ![Interrater Agreement Plot.png](https://www.statgraphics.com/hs-fs/hubfs/Interrater%20Agreement%20Plot.png?width=641&height=401&name=Interrater%20Agreement%20Plot.png) # Something to say? ### Subscribe to our blog: The Statgraphics Blog is designed to share knowledge and ideas amongst all members of the Statgraphics community. We welcome your comments and suggestions regarding the topics posted. In addition, let us know if there are other topics that you would like to discuss. 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