... 177–184,Sydney, July 2006.c2006 Association for Computational LinguisticsTrace Prediction and Recovery With Unlexicalized PCFGs and Slash FeaturesHelmut SchmidIMS, University of Stuttgartschmid@ims.uni-stuttgart.deAbstractThis ... bracketing, EC prediction, and co-indexation (CI) and the f-scores without the spec-ified feature.5 ComparisonTable 7 compares the empty category prediction results of our parser with those reported ... precision.Table 7 shows the trace prediction accuraciesof our parser, Johnson’s (2001) parser with parserinput and perfect input, and Campbell’s (2004)parser with perfect input. The accuracy...