Combining thermochemical data from various sources (typically of very different fidelity) is necessary to achieve better agreement with experimental gas-phase reaction enthalpies or more accurate ∆ f H of the adsorbates. This combination of data leads to changes in relative quantities in the thermochemical network that either implicitly or explicitly "correct" reaction enthalpies to be more consistent with higher-fidelity data. Schemes are available that apply these corrections to a few species, many species, or sometimes all species in the thermochemical network. Here, we classify approaches as "direct" correction schemes, where individual DFT energies are explicitly corrected, and "indirect" correction schemes, where corrections are made implicitly through error cancellation reactions. The direct methods tend to be simpler because they apply fewer corrections and can be understood intuitively, but they typically do not exactly reproduce all known quantities. In contrast, indirect methods are generally capable of reproducing known quantities exactly, but they do so at the expense of greater complexity and less transparency.