Comparison between cell connectivity patterns generated by the models and observed in the chick basilar papilla. The horizontal axis represents the alternatives studied in . On the left are the observations from embryonic day E9 and the right observations from embryonic day E12. Measurements from two distinct spatial regions CD (central distal) and SP (superior proximal) are given. The vertical axis represents the end-states of Models 0 through 4. To compare each basilar papilla region with each model output, the measurements of secondary-primary cell connectivity are matched by computing the root mean squared error (rms). This rms error is calculated by comparing the distribution of the number of primary cells around each secondary cell. Data for the basilar papilla is taken from the graphs shown in the right column of Figure 11 from . Data for the models is taken from the graphs given in Figure 9(c).