This allows for the easy comparison of the different models outlined by Campbell et al., within a Bayesian framework. This method is easily generalisable to any reflectometry model comparison investigation . Furthermore, it also allows for the comparison of models with different numbers of variable parameters, enabling the quantification of the information density available to a given reflectometry dataset. However, this final point is beyond the scope of the current work and will be the subject of future work as this enables the quantification of information contained within a given experimental dataset.