A Bayesian Model for Generative Transition-based Dependency Parsing
Table 6: Language modelling test results. Above, training and testing on WSJ. Below, training semi-supervised and testing on WMT.
['Model', 'Perplexity']
We note that the perplexities reported are upper bounds on the true perplexity of the model, as it is intractable to sum over all possible parses of a sentence to compute the marginal probability of the words. As an approximation we sum over the final beam after decoding.