1. Interest in Variation Over Time T
   1. Discrete (or discretized) Timepoints Ti (i=1,...,N)
      1. Any number of Timepoints
         1. ECDF plots grouped by time point
            1. with T as group variable (line color/type)
            2. with T as panel variable
      2. For 2 time points only
         1. Facing Histograms
         2. Buttefly plots
   2. Continuous timepoints