life stages with duration and mortality A data structure that refers to (1) a subpopulation of a population based on life stage, (2) the rate of mortality of that subpopulation, and (3) the average duration of time that the individuals in the subpopulation spend in that life stage. A data structure that refers to (1) a subpopulation of a population based on life stage, (2) the rate of mortality of that subpopulation, and (3) the average duration of time that the individuals in the subpopulation spend in that life stage. William R. Hogan LifeStageWithDurationAndMortality Matthew Diller data representational model