In this case, we consider that the effort is equal to k. As a consequence, for small ks the effort required to establish co-referential links is similar for both theories, because both can establish only a limited number of links.
as k increases, the effort computed over the entire corpus diverges dramatically: using the Discourse-VT model, the search space for co-referential links is reduced by about 800 units for a corpus containing roughly 1200 referential expressions.