statisticalrethinkin..

13.3. VARYING EFFECTS AND THE UNDERFITTING/OVERFITTING TRADEOFF 347logistic( 1.1 )R code13.11[1] 0.7502601So the average rate of survival in the population of ponds is just around 75% (in this simulation—yours will differ some). To get the expected probability of survival for any pond j, just addthe varying intercept for it to α. For example, for pond 1:logistic( 1.1 + 1.54 )R code13.12[1] 0.933392Now that we’ve found these estimates, let’s compute the predicted survival proportions,according to them, and add those proportions to our growing simulation data frame. I’llcall the column varying.pi, to indicate that is contains the expected per-pond survivalprobabilities, derived from the varying effect estimates.estimated.aj