The simplest before-and-after study involves three stages: 1 observe and measure a public; 2 expose the public to a public relations tactic; and 3 measure the public again. Any change in the public's awareness, acceptance or action can likely be attributed to the tactic.
Remember,however, that public relations activities generally don't take place in a vacuum or in a pure environment. Be aware of extraneous factors. Not every change in your key public may appropriately be linked, cause-and-effect fashion, to your programming. One of the challenges for evaluative research is to sort out the effective public relations tactics from unrelated outside forces.