This paper describes a series of experiments to test the hypothesis that the parallel application of multiple NLP tools and the integration of their results improves the correctness and robustness of the resulting analysis. It is shown how annotations created by seven NLP tools are mapped onto toolindependent descriptions that are defined with reference to an ontology of linguistic annotations, and how a majority vote and ontological consistency constraints can be used to integrate multiple alternative analyses of the same token in a consistent way. For morphosyntactic (parts of speech) and morphological annotations of three German corpora, the resulting merged sets of ontological descriptions are evaluated in comparison to (ontological representation of) existing reference annotations. 1 Motivation and overview NLP systems for higher-level operations or complex annotations often integrate redundant modules that provide alternative analyses for the same linguistic phenomenon in order ...