I've put up a brief posting here: http://bicep0.caltech.edu/~spuder/analysis_logbook/analysis/20131113_signfl… pointing out that our sign-flip noise realizations are not assigning the same sign to simultaneous BICEP2/Keck Array tags, and therefore are not simulating noise correlations between the experiments. This was surprising to me, as I thought the major benefit of sign-flipping noise sims was the ability to account for correlated noise. Our sims then have zero noise correlation between BICEP2 and Keck Array, and we're not applying any noise debias to the cross-spectra. Perhaps all of this is OK if we can prove that the noise correlations are negligible, but I don't recall that having been demonstrated. Has there been a deliberate decision not to match the sign-flip sequences, or does it indicate something broken in the driver code? - Walt