Failure rate：The proportion of missing genotypes. Genotypes are classified as missing if the genotype-calling algorithm cannot infer the genotype with sufficient confidence. Can be calculated across each individual and/or SNP.

False-negative/False-positive：假陰性/假陽(yáng)性

Genotype call rate：The proportion of genotypes per marker with non-missing data.

Heterozygosity rate：The proportion of heterozygous genotypes for a given individual.

Linkage Disequilibrium：Non-random association of alleles at two or more loci.

Population substructure：The presence of distinct groups of individuals with subtle differences in allele frequency such that genetic data can be used to cluster these individuals into separate groups.

Principal components analysis：A mathematical procedure for calculating a number of orthogonal latent variables that summarize a data matrix containing many potentially correlated variables.

r2：A measure of the linkage disequilibrium (genetic correlation) between two markers. An r2?of 1 indicates that the two markers are perfectly correlated and an r2?of 0 indicates that the two markers are completely independent.