what model would pooling mean why do we do pooling why is pooling an useful parameter in the regression model when is pooling appropriate when data is missing from a multilevel regression model why use pooling in hierarchical modelling how do you pool data in a hierarchical model why pool the data why is pooling used in hierarchical modelling why is pooling needed what occurs if the data do not exist why do you use pooling what does it mean when a patient is randomly pooled when data sparse at random when can the data not be sparse? why is pooling appropriate for a patient what is pooling why does pooling work in a research study what is pooled data what does pooling mean for a model