TY - RPRT T1 - Comparing causal-link and propositional planners: Tradeoffs between plan length and domain size Y1 - 1999 A1 - Memon, Atif M. A1 - Pollack,M. A1 - Soffa,M. L AB - Recent studies have shown that propositional planners, which de-rive from Graphplan and SATPLAN, can generate significantly longer plans than causal-link planners. We present experimental evidence demonstrating that while this may be true, propositional planners also have important limitations relative to the causal-link planners: specifically, they can generate plans only for smaller domains, where the size of a domain is defined by the number of distinguishable objects it contains. Our experiments were conducted in the domain of code optimization, in which the states of the world represent states of the computer program code and the planning operators are the optimiza- tion operators. This domain is well-suited to studying the trade-offs between plan length and domain size, because it is straightforward to manipulate both these factors. On the basis of our experiments, we conclude that causal-link and propositional planners have complementary strengths. PB - Technical Report 99-06, University of Pittsburgh, Pittsburgh ER -