Caption: Invariant kaon production cross section versus kaon momentum for data along with the results of the scaling fit to data with 1.2 < 5.5 GeV. The PK, θK, invariant cross section fits and the data points have been scaled to a beam energy of 8.89 GeV assuming Feynman scaling. The plot shows the data and fit results for kaon production angle bins between 0.000 < θK < 0.250 rad. The points are the data from the various experiments with the experiment's actual beam momentum indicated in the legend. The solid curve is the best fit to the data and the dashed curves show the uncertainty assumed for the MiniBooNE oscillation analysis.