Pe'er I, de Bakker PIW, Maller J, Yelensky R, Altshuler D, Daly MJ: Evaluating and improving power in whole-genome association studies using fixed marker sets.Nat. Genet.38(6), 663–667 (2006) . This study compares and contrasts three different high-density single nucleotide polymorphism genotyping platforms using data generated on the 270 HapMap samples. The differences in minor allele frequencies are evaluated, coverage across the entire genome using r2 and then the coverage of the ENCyclopedia Of DNA Elements (ENCODE) regions is compared using both a single- and multi-point evaluation. All of these analyses are carried out on the three HapMap populations.