Rehbein, Inesvan Genabith, Josef2007-11-302007-11-302007-11-301736-6305http://hdl.handle.net/10062/4813Proceedings of the Sixth International Workshop on Treebanks and Linguistic Theories. Editors: Koenraad De Smedt, Jan Hajič and Sandra Kübler. NEALT Proceedings Series, Vol. 1 (2007), 115-126. © 2007 The editors and contributors. Published by Northern European Association for Language Technology (NEALT) http://omilia.uio.no/nealt . Electronically published at Tartu University Library (Estonia) http://hdl.handle.net/10062/4476 .enWhy is It so Difficult to Compare Treebanks? TIGER and TüBa-D/Z RevisitedArticle