Just take a look to the most popular of the existing models of evaluation proposed by PR scholars. Cutlip et. al’s evaluation model (1985) is known as PII (Preparation, Implementation, Impact). The first step of preparation assesses the adequacy of background information, the appropriateness and quality of message. Implementation examines the number of messages sent to the media and who received them. Finally, impact evaluates the changes in opinion, attitudes and behaviours.
MacNamara’s Macro Model (1992) represents public relations programmes in a pyramidal form with three layers: inputs, outputs and results. The difference to the previous model is that it proposes methodologies, which can be applied to each of the steps, in order to develop a complete process. “MacNamara says that it presents a practical model for planning and managing evaluation of public relations and recognizes communication as a multi-step process” (cited in Kitchen, 1997, p.292).
Lindenmann’s yardstick (1993) also sets a three-level approach, with objectives set beforehand. The first basic level measures outputs, such as media placements. The second intermediate level judges the number of messages received by the target audience, and the last advanced level examines outcomes, such as attitude changes (Theaker, 2004, p.302).