There has been much discussion (see here and here for a few examples) of the so-called “Scandinavian Problem” with AncestryDNA‘s ethnicity estimate, in which certain populations appeared to be over-represented in the reference panel utilized by Ancestry.com. I, for example, have no documented Scandinavian ancestry, but had 78% Scandinavian. Many others experienced the same issue.
The AncestryDNA team were well aware of the issues, and have been working on an update to their ethnicity algorithm, reference panel, and user interface. Indeed, at “The First DNA Day at the Southern California Genealogy Society Jamboree” in June of this year, Ken Chahine (Senior Vice President and General Manager, DNA) gave a presentation in which he announced that the ethnicity calculations at AncestryDNA were undergoing a complete overhaul and a major update would be provided to all customers later this year.