||Recent advances in the study of archaic hominin DNA have resulted in the rapid development and application of new methods designed to test our relationship to our nearest relatives. These methods have been applied with archaic samples in contexts with ghost admixture, sparse sampling, ascertainment bias, and poorly understood historical events. They have also been applied to modern samples with complex relationships which will exacerbate the same problems. Here, we introduce a new method for estimating the admixture fraction, and test it and several previous methods to determine their sensitivity to the above problems. Finally, we apply these methods to Single Nucleotide Polymorphism (SNP) microarray and whole genome data, and compare our estimates to those published previously.