The poster “Genotype Error Detection and Imputation using Hidden Markov Models of Haplotype Diversity” (ppt, poster abstract) received the best poster award at ISBRA 2008. The poster describes GEDI, a software package for genotype error detection and imputation of genotypes at untyped SNP loci based on reference haplotypes such as those available in HapMap. Detection of genotyping errors and imputation of missing genotypes is based on multi-locus genotype likelihoods efficiently computed using an HMM that captures the linkage disequilibrium in the population under study. With a runtime that scales linearly both in the number of markers and the number of typed individuals, GEDI is able to handle very large datasets while achieving high accuracy rates for both error detection and imputation.