Figure 2:

Schematic of model calibration, selection, and validation framework. A determistic or statistical (panel a) approach to model calibration is used to minimize the error between the model and the measurement of a specific quantity of interest (e.g., tumor volume, cell density distribution). In this example, the model is initialized at time point 1 (t₁) and the error is calculated at time point 2 (t₂) Model selection (panel b) criterion are used to select the most appropriate model that accurately describes the data. The selected model is then evaluated in a validation stage (panel c) by simulating tumor growth at t₃ and comparing it to the measured tumor growth. If the model error is within a prescribed error threshold for a quanity of interest the model is then considered valid.