IE concentrates on domain-specific texts of similar types, corpus linguistics is often concerned with large designed collections of heterogeneous texts drawn from numerous domains. Systems exist which allow querying of texts annotated by IE techniques. This holds out the hope that corpora, annotated according to IE techniques, could then be queried more flexibly and in different informative ways than at present. Corpus linguistics has developed a battery of sophisticated statistical techniques that could contribute to IE tasks, based on e.g. dispersion, association scores, etc. They thus do not have the benefit of automatically derived corpus evidence to guide them.
Systems are able to process large amounts of data at high speed.
With a traditionally-annotated corpus, there is really only one view, that of the original annotators. There has also been at least a tacit assumption that one applies some technique or some annotation to an entire corpus one is working on. That is, in building a treebank of partially analysed sentences, each sentence has been analysed to some degree. However, it seems not unreasonable to suggest that a corpus might be only partially analysed, via IE techniques, where perhaps certain sentences of the corpus may not receive any annotation at all. Although this makes it difficult to have any overall judgement, one however asks if an overall judgement makes any sense in such a context.