Comparison between self-reported ancestry and structured estimated ancestry proportion. Ideally without admixture, each group would be represented by just one bar. That is if the vector Q = (q1,q2,q3,q4) represents the ancestry score for each individual in the dataset, Q should have 3 of its components equal to 0 and one component equal to 1. As can be seen from this figure, this is not the case. Self-reported ancestry is again less reliable for the Hispanic-American population since its graph seems to be the farthest away from the ideal situation.
Divers et al. BMC Genetics 2011 12:28 doi:10.1186/1471-2156-12-28