Estimators for Stochastic ``Unification-Based'' Grammars
  Log-linear models provide a statistically sound framework for Stochastic ``Unification-Based'' Grammars (SUBGs) and stochastic versions of other kinds of grammars. We describe two computationally-tractable ways of estimating the parameters of such grammars from a training corpus of syntactic analyses, and apply these to estimate a stochastic version of Lexical-Functional Grammar. 
Mark Johnson, Stuart Geman, Stephen Canon, Zhiyi Chi and Stefan   Riezler