Ancestry is Updating Ethnicity Estimates

Ancestry is continuing to roll out new ethnicity estimates "with increased precision." This has been underway since last September to selected clients. Now Ancestry announces that if you've not received new estimates you soon will. "Starting May 30, 2019, all AncestryDNA® customers will be transitioned to their new, "more precise" ethnicity estimates.  Prior results may be downloaded by July 20, 2019."

The main change for me was an increase in the percent for England, Wales & Northwestern Europe from 19% to 44%. Ireland & Scotland had a small increase, European Jewish a small decrease, 11% Scandinavian became 3% Norwegian. I'd speculate the balance transferred to England, Wales & Northwestern Europe. Three smaller categories no longer appear.

Ancestry explains the changes as due to:

• Larger Reference Panel - We've added 13,000 more samples to our reference panel, which increases our ability to identify and find the genetic signature of a region within one’s DNA. 
• Improved Algorithm - A new algorithm analyzes longer segments of genetic information in combination with analysis of DNA samples from Ancestry’s expanded proprietary population reference panel. 
• New regions - The newly enhanced version of our ethnicity estimate includes more regions in Asia and Europe. For example, we have expanded our regions in Asia to include Western and Central India, the Philippines, Japan, Korea, and Northern China. Also, Scandinavia can now be reported more specifically as Sweden or Norway.

Technically precision is "refinement in measurement, calculation, or specification, especially as represented by the number of digits given." As the new estimates give the same number of digits as before Ancestry isn't using precision in the technical sense but as a synonym for accuracy.