Firstly, the best way to ensure accurate facial recognition is to tag a few faces of each person you want recognized right in the beginning, and then allow Face Detection to start scanning more files. Facial Recognition will work better and better the more correct examples it has. Essentially you need to “train” it a bit to recognize each person. This applies to any incorrect names you find too. The earlier you correct them, the less likely they are to influence recognition in the future.

Here’s some approaches to help you with incorrectly-named faces:

In Manage mode, Tools | Face Detection, there is the "Rerun Recognition" command. When you select one or more photos, this command will clear names from all automatically-named faces in the selection, leaving the manually-named faces alone. Then it will rerun Facial Recognition on each unnamed detected face in the selection. Once you have a few manually labeled examples of each person, this command will help you to correct many of the incorrectly named faces.

The only issue with this tool is that if you miss an incorrectly named face and don't have it selected, it will continue to interfere. So, we added the Rerun Recognition command in Tools | Options | Face Detection. This works exactly like the command in the menu, except that it runs on the entire database.

After running one of these commands, you will most likely find that there are still a few incorrectly named faces. Renaming a few of these manually and rerunning recognition again will make the set of labeled faces progressively more and more correct. In our tests, we found that even one pass significantly improved the number of correctly-labeled faces.