Retraction statutes vary from state to state, and you should be extremely careful not to admit fault or otherwise preclude defenses in case a claim is filed later . Always have legal counsel review any such correction or retraction before it is broadcast. Given that tone, it is perhaps not surprising then, that corrections are heard infrequently. Morning Edition does it every two to three weeks. Saturday , not at all.
Producers use it as a device to address listeners' concerns and to run corrections.
Producers also use it as a timing device if there is a two or three minute hole in the show. Whenever NPR airs a correction, it should be appended to the original transcript to make sure the record is amended as newspapers do. One solution would be to use the NPR Web site. Correcting major errors seems unquestioned as a matter of policy. But they represent an important principle.