 In particular, Smith takes issue with Kellert’s view that chaos explanations are, in the main, qualitative rather than quantitative. He points out that we can calculate Lyapunov exponents, bifurcation points as control parameters change, and even use chaos models be predict the values of evolving dynamical variables—“individual trajectory picture”—at least for some short time horizon. So perhaps there is more quantitative information to be gleaned from chaos models than Kellert lets on (this is particularly true if we turn to statistical methods of prediction). Furthermore, Smith argues that standard physics explanations, along with quantitative results, always emphasize the qualitative features of models as well. 