When books are returned to Countway, they go through a three-step process:

  1. An initial check-in, to discharge the item from the borrower's account and re-sensitize the electronic security measures.
  2. A second check-in, to discharge the item from the borrower's account and re-sensitize the electronic security measures. This is done to ensure that the item was not missed in the first check-in.
  3. Books are reshelved.

Each of the above steps are done at different times and by different people. Several years ago, we used a different procedure, in which only steps 1 and 3 were completed, and we occasionally made errors. In the years since we introduced the deliberately redundant system outlined above, we have successfully eliminated check-in errors. The current system has a further advantage in that it allows us to detect cases in which a borrower with an overdue book has attempted to circumvent the system by reshelving the item directly.

For a book that was returned properly to not be discharged from the borrower's account and not be returned to the correct shelf location would require, at minimum, that three separate errors be committed by three different people at three distinct times.