IMPORTANT LEGAL NOTICE - The information on this site is subject todisclaimercopyright notice
  EUROPA > European Commission > EuropeAid > Evaluation > Methodology > Glossary
Last updated: 03/05/2005


• Evaluation Guidelines
• Methodological bases
• Evaluation tools
• Examples
• Glossary
• Sitemap


OECD definitions

In 2002 the OECD published a glossary of key terms in evaluation and results-based management  (Development Aid Committee - Working Party on Aid Evaluation). Initially issued in English, French and Spanish, it has been subsequently translated in many other languages. It is part of a common effort of the development aid community, including the European Community, to reduce the terminological confusion and to promote common vocabulary.

EC definitions

The Financial Regulation establishes a framework which applies to all EC policies. This framework has been translated into evaluation guidelines and a glossary issued by the Directorate General Budget.

Comparing definitions

Both OECD and EC definitions should be regarded as equally legitimate in the context of EC external assistance evaluation. An in-depth comparison has been undertaken with the result that:

almost all terms are defined consistently

Only four couples of definitions are different enough to raise significant risks of misunderstanding:

Risks of misunderstanding (four terms)



Impact … long term effects produced by a development intervention … A general term used to describe the effects of an intervention on society …
Outcome The likely or achieved short-term and medium-term effects of an intervention's outputs. The longer-term impact usually expressed in terms of broad socio-economic consequences
Result …The output, outcome or impact (intended or unintended, positive and/or negative) of a development intervention. The initial impact of an intervention …
Efficiency A measure of how economically resources/inputs (funds, expertise, time, etc.) are converted to results (considering OECD's definition of results, efficiency may relate to outputs or to any level of effect) The extent to which the desired effects are achieved at a reasonable cost
(a definition which does not cover outputs)

The following options have been taken in order to design these guidelines

Options taken

  Basic glossary


Impact OECD … long term effects produced by a development intervention …
Outcome the term has been neither used nor defined

Result EC The initial impact of an intervention …
Efficiency Merged (based on OECD) The extent to which outputs and/or the desired effects are achieved with the lowest possible use of resources/inputs (funds, expertise, time, admin-istrative costs, etc.)

The key concepts of the intervention logic can be compared as follows:

Intervention logic: key concepts compared

Level These guidelines OECD
EC Financial
1 Output Effect Output Result Output
2 Result Out-
Result Impact
3 Impact Impact Out-
1 Good and / or service produced / delivered by the intervention (e.g. rehabilitated road)
2 Initial change attributable to the intervention (e.g. reduced transport time and cost).
3 Further long term change attributable to the intervention (e.g. development of trade)


In other publications issued by the EC, the term results can be used in the wider sense, as defined by OECD-DAC, e.g. Result-Oriented Monitoring