What are the considerations for using wide-reaching messages and training over individual-focused efforts for changing behavior? In most places that I've worked, when some sort of problem arose or corrective action needs to be taken, one of the first responses is to send mass emails at an organization or team level and set up mandatory group training sessions. Sometimes, this is in place of an effort to correct individual actions that led to the problem on a personal level.

Does the use of broad messages (email, group training, individual training mandated for all individuals) have an impact on behavior that is equal to or greater than the use of individually-focused efforts?

I realize that in some cases, the occurrence of a problem could indicate a lack of training that does need to be addressed at a larger level to minimize future occurrences. I also realize that that some incidents might be accidental - the person realized that they did or didn't do something and personally took corrective action to prevent it in the future. However, I'm especially interested in cases where an individual performed some type of action (or inaction) that led to the occurrence of a problem and did not take corrective action on their own and if group-oriented messages have a chance of changing their behavior.
The first thing that comes to mind when reading this is diffusion of responsibility. Because responsibility has not been explicitly assigned, as it would be in a one-on-one meeting, people tend to feel like they do not need to do anything.