Cauchy-characteristic extractions (CCE) avoids the errors due to extraction at finite worldtube. The Cauchy and the characteristic approaches have complementary strengths and weaknesses. Unification of the two methods is a promising way of combining the strengths of both formalisms.
Babiuc-Hamilton, M. C. (2009, June). Cauchy-characteristic patching with improved accuracy. Slides presented at the 12th Eastern Gravity Meeting, Center for Computational Relativity & Gravitation, Rochester Institute of Technology, Rochester, NY.