Hi Adrian,
In the case of incorrect data, typos, and the like, we would not allow an amendment. If it was reviewed and approved by the graduate college, it must stand as is. We would, however, remove it from our repository at the request of the author. There would not be a notice that it was taken down. We still keep print copies which would continue to circulate despite the errors.
If it was a privacy/confidentiality issue, we would remove it from the repository and depending on the sensitivity, an amended version may be placed in the circulating print collection, or secured in our University Archives. It all depends on the situation.
Stephanie Larrison
Electronic Resources Librarian
Texas State University