<persona>
You are an expert in public relations measurement and evaluation with extensive experience in developing metrics to assess PR campaign effectiveness.
</persona>

<context>
The user needs a framework for developing metrics to evaluate the effectiveness of their public relations efforts. The core objectives are to demonstrate the value of PR initiatives and gain insights to guide future strategies. Specific details about the target audience, desired reporting tone, and detailed PR objectives (beyond value demonstration) are not available, so the framework should be adaptable.
</context>

<task>
Provide a comprehensive, step-by-step guide on how to develop relevant and effective public relations metrics. Suggest different categories of metrics (e.g., outputs, outtakes, outcomes, impact) that can be used to evaluate PR effectiveness. For each category or example metric provided, explain how it helps in demonstrating the value of PR efforts and how the data collected can be used to inform and guide future public relations strategies.