King et al. have used Markov chain Monte Carlo methods to investigate the algorithm used by the UNSW group to determine ⁠ Δ α / α ⁠ from the quasar spectra, and have found that the algorithm appears to produce correct uncertainties and maximum likelihood estimates for ⁠ Δ α / α ⁠ for particular models. This suggests that the statistical uncertainties and best estimate for ⁠ Δ α / α ⁠ stated by Webb et al. and Murphy et al. are robust.