The graphs and contour plots generated by Auto-VTNA (Fig. and, respectively), allow individual overlay plots to be produced in an interactive manner through mouseclicks (Fig. ). By left-clicking on the graph or contour plot, a traditional overlay plot is generated, whereas right-clicks show the plot with normalised y axis, the fitted function, and the overlay score of the click order value(s). This allows the operator to interrogate the overlay score landscape obtained by Auto-VTNA and verify that the calculated reaction order(s) give optimal concentration profile overlay.