Ensure the user can update the data
"One judge, however, accidentally punched in a mark of 8.7 instead of 9.7. While the mistake was immediately admitted, officials refused to change Fréchette's official score and the champion swimmer was relegated to second place. " Canada's Sports Hall of Fame - Sylvie Fréchette
As Sylvie Fréchette was a Canadian the video of the judge on the TV news back in 1992 frantically running around trying to get someone to change her score stuck in my mind all these years.
A newsgroup poster asked about how to handle bar code scanning in a serial number in a factory and then somehow indicate "Pass" or "Fail". I gave the poster some suggestions but added "always make sure the user can go back and change things. Mistakes happen and you have to allow them to change things. "
Now clearly you can't always do this. In many financial systems you want to have an audit trail of any such changes. Or the users simply aren't allowed to change things but must key in adjusting entries. Or maybe you give the user to the end of the shift before locking fields or require supervisors to make any changes. Or once a transaction has been invoiced it can't be updated.