Skip to content

Good Practice

What are you looking for?

There is no one single impact assessment system. Every organisation must develop a plan that is adapted to its own circumstances. For this to be a success, ZEWO recommends that an organisation should follow the following principles for high-quality assessments and disclosure and dissemination of results:


  • Plan
    The organisation has an impact assessment plan that is adapted to its circumstances. This provides information about who uses which methodology when and how often to assess effects on the target groups.
  • Frequency
    The organisation regularly measures the outcomes on the target groups.
  • Budget
    The organisation devotes between 0.5 and 2.5% of its annual project budget to implementing and carrying out impact assessments.
  • Level of comparison
    The organisation interprets an outcome or impact assessment as at the very least a before-and-after comparison. A description of a state of affairs is not considered to be an impact assessment.


  • Plan
    The organisation discloses the principles of its impact assessment system, the time schedule and the methods it uses.
  • Results
    The organisation publishes the results of the impact assessments carried out according to plan during the reporting year in its annual performance report. This includes in particular statements about:
    Outcome and impact objectives: the intended results for the target group
    Outputs: a presentation with reference to the inputs and the achievement of the objectives;
    Outcomes: a description of the changes for the target group as well any changes compared to the control group;
    Impact: if possible, a description of the contribution to the overarching goals and longer-term impact.
  • Reports
    Reports on the outcome and impact of individual projects and programmes are disclosed to funders at the very least.
  • Costs
    It is also desirable to reveal the expenses related to impact assessment.


  • Summary
    The findings may be aggregated by subject area or region as long as the chosen methods permit this.
  • Accuracy
    Assertions about the outcomes and impact achieved are adapted to the meaningfulness, accuracy and reliability of the chosen methods. In particular, it is clear whether the effects of a specific project or programme can be proved beyond doubt or whether a plausible case has been made for it.
  • Completeness
    No essential information has been withheld that might distort the overall picture. This means, in particular, that it is not simply positive examples that have been presented while negative aspects have been omitted.
  • Correctness
    If assertions are used for advertising or fundraising, then the facts must be verifiable.
  • Time period
    The organisation discloses when the assessment was conducted and to which period of time the respective assertions refer.