Comparison of the X(z)-reconstructions obtained using different values of the correlated prior parameters a_c and σ_m, and the range Δ_X over which X can vary in each bin. The discrete error bars show the 1σ uncertainties from the prior alone. Panel (C) is the case of our standard prior, also shown in Figure 4. Note that the vertical axis range in panel (G) differs from that in other panels.