uncountable setundecileundercount in decennial censusunderestimationundirected graphunequalunequal probability samplingunfoldingunicluster designunidimensionalityunificationuniformuniform convergenceuniform distributionuniform distribution modulo 1uniform metricuniform normuniform sampling procedureuniformityuniformity trialsuniformizationuniformly absolutely convergent seriesuniformly consistent testuniformly convergent sequenceuniformly convergent seriesuniformly minimum variance unbiased estimatorunimodalunimodal regressionunimodalityuninformativeness of a likelihood functionunionunion intersection principleunion of setsunique factorizationuniqueness conditionuniqueness principleuniqueness theoremunitunit matrixunit root testunitary matrixunivariateunivariate distributionuniversal dominationuniversal probability generating functionunlikelihoodunobservable random variableunreliability functionunrestricted random sampleunstable state
