1.1 Background and Modeling Process

2.1 Gridded Population Modeling
The paper uses modeling methodology similar to the WorldPop project that is based on Random Forest \cite{breiman2001random} ensemble based learners to model population density. Figure 1 provides a flow diagram provides an overview of the workflow, slightly modified from \cite{Stevens_2015}.
The model uses next available coarser level of admin units to estimate the population density of and finer level of coarser units are preserved to validate the model by calculating various performance measures.