The fourth and final step amounts to constructing topic-dependent BAFs from reviews, for the purpose of assessing how "good" the item being reviewed is by assessing the dialectical strength of a special argument G (for "good") in the constructed BAFs.
in turn, each topic t identified at Step 2 gives a special argument G t (for "good as far as t is concerned") supporting G. intuitively, the stronger the various G t in the computed BAFs, the stronger the G. in addition to these special arguments G t supporting G, the BAFs also include relations between arguments related to topic t drawn from reviews and G t , so that a newer argument (with respect to time) can either support, attack, or neither support nor attack a previous argument or G t , but not vice versa.