The design and use of microporous solids depends on having access to characteristics such as the pore volume and surface area. Comparison methods such as the cc, method are one of the most widely used means of determining these parameters. An assessment of this group of methods was undertaken by comparing estimates obtained from them using adsorption isotherms generated by grand canonical Monte Carlo simulation on a selection of model nanoporous solids with exactly known surface areas and pore volumes. Conclusions are drawn from this absolute assessment in regard to the validity of the a, method for determining the micropore volume, the mesopore surface area, and the separation of pore groups based on the concept of primary and cooperative filling, the subtracting pore effect (SPE) method, and the required character of the reference surface.