Year: 2008 Human judgements in parallel treebank alignment

We have built a parallel treebank that includes word and phrase alignment. The alignment information was manually checked using a graphical tool that al-lows the annotator to view a pair of trees from parallel sentences. We found the compilation of clear alignment guidelines to be a difficult task. However, experi-ments with a group of students have shown that we are on the right track with up to 89 % overlap between the student annota-tion and our own. At the same time these experiments have helped us to pin-point the weaknesses in the guidelines, many of which concerned unclear rules related to differences in grammatical forms between the languages.