What do you think?

I have stated before that so far my reserach show that PSAs can't realisticaly change behavior and thus we should not expect such an outcome. Yet in Wikipedia's definition of a Public Service Announcement it is written : " (...)PSAs are intended to modify public attitudes ..." \Does this mean that
1- there is a gap between the intentions behind PSAs and the actual reality of what they can do?
2- or that the resources I am using are wrong for stating that PSAs can't in themselves change behaviors ?
3- or maybe the word attitude here refers to something other than "behavior."

WHAT DO YOU THINK?

Now I understand that Wikipedia is not a scholar resource, therefore - something I did not think of before - I will research to find out what is the definition for PSAs according to more creditable resources.