I can elaborate on that! We talk about the general approach in our MuttMix survey FAQ: http://iaabcprojects.org/faq/ In fact, many of the dogs you see in the Pup Quiz are Darwin’s Dogs whose owners provided photos and videos for part 1 of the quiz. We are planning a part 2 which may include new mutts!
Linda and Diane from our lab also wrote an IAABC article on this, called “How Accurate are those Dog DNA Tests?” It’s a lot more detailed than the FAQ, but has great illustrations.
In addition to breed percentages, we will also be giving extra information: how confident we are for each breed call, how confident we are that a dog is mixed or purebred, and whether we think your dog may have a breed that is not in our reference panel. We also do not hide missing data — if the algorithm says a portion of your dog’s DNA is uncalled for any known breed, then we tell you that portion.
Also, as we improve our reference panel, your dog’s results may become more refined over time. Some breeds are under-represented and we will be looking for more to add to the panel, by reaching out to owners through Darwin’s Ark.