Parameter and sensitivity identifiability for increasing error. Increasing ξ results in a corresponding decrease in the confidence of the parameter and sensitivity estimates. Violin plots of the parameter values (left) and relative period sensitivities (right) show the distribution of values from each parameter estimation. In the plots, a box plot is superimposed above a kernel density plot to convey the distribution of values. The whiskers used extend to the most extreme data point within 1.5x the inner quartile range. Sensitivities in which the 5 th and 95 th percentile values span the x-axis are deemed non-identifiable (red), as the model’s response direction can not be accurately estimated. Higher ξ also results in wider parameter distributions.