seasonalitysecant methodsechsech squared distributionsecond ordersecond order efficiencysecondary datasecretary problemsectorsector chartsector diagramsecular trendseemingly unrelated regressionsegregationseismogramselect life tableselection biasselection differentialselection of regression variablesselection of stratifiersselection problemselection procedureselection statisticselective inferenceselective least squaresselective procedureselective samplingself adjoint matrixself affine processself consistencyself consistent estimatorself correcting processself enumerationself reciprocal distributionself similar processself similarityself weighting samplesemanticssemi bayesian inferencesemi dissipative markov chainssemi interquartile rangesemi inversesemi latin squaressemi markovsemi markov processsemi midmeanssemi parametric modelsemi pie diagramsemi sextilesemideterministic relation