The analyses of Georgian and Swahili discussed above illustrate the main revisions to the ‘control structure’ of realizational approaches that have been proposed to extend their descriptive scope. As these accounts show, assumptions about intrinsic and extrinsic ordering are highly interdependent, so that revisions of one component tend to impact the other. In the analysis of Georgian proposed by Anderson (1986, 1992), the assumption of a (partially) linear block structure requires an extension of a disjunctive ordering condition. In the analysis of Swahili proposed by Stump (1993c), the blocking relation between agreement markers motivates a revised conception of blocks. Among the more framework-specific revisions are proposals for dissociating block order from exponent serialization, to account for patterns in which common elements occur in different orders (Stump 1993c, 2001; Luis and Spencer 2005).
Before turning next to formalism-specific extensions, it is worth reprising some of the basic points of agreement and disagreement within realizational models. There is broad agreement that rule application is constrained by a disjunctive ordering condition but no consensus about the form of that condition. Most realizational analyses assign rules to blocks, and justify the composition of individual blocks. However, there is rarely any explicit rationale provided for the organization of blocks into a linear (or nested) structure. Some approaches make extensive use of referral rules, while others eschew them altogether. The sole thread that runs through the family of realizational models is the use of exponence rules to relate ‘units of meaning’ and ‘units of form’.