A random thought occurred to me. Most word processors people use for
editing (that is, WordPerfect and Word) have built-in indexing
features. One way to check for repeat answers would be to flag each
answer, and then build an index at the end, which could be used to
scan for repeats relatively quickly. [Moreover, if people used
subdocument features, it may not necessary to build a single long file.]
Just a thought.
--AEI