Evaluation should be guided by agreed terms of reference (TOR), which specify the scope and nature of the evaluation, and define the evaluators’ roles. The TOR should include:

• Background information about the campaign to be evaluated, the issue it addresses and key stakeholders
• Purpose of the evaluation
• Intended uses and users of the evaluation findings
• Key issues to be studied in the evaluation and questions to be answered
• Principles and approach that will guide the evaluation
• Methodology (e.g. data collection and presentation, inclusion of beneficiaries)
• Roles and responsibilities of those involved in the exercise
• Reporting requirements
• Budget for the evaluation
• Timeline and milestones

For more details on TOR writing, see IDRC, 2004. Writing Terms of Reference (ToRs) for an Evaluation.