This correcton task ranged from the simple, such as connecting two sentences in one corpus that were erroneously broken, to the middling, such as joining two tokens in Sem-Cor that comprised a hyphenate in Brown, to the difficult, such as correcting egregious parse annotation errors, or annotating entire sentences that were omitted from SemCor.
the case of hyphenates was quite frequent, as it was the default in SemCor to split up all such words and assign them their individual word senses (synsets).