4. To learn more about Impact Evaluation

4.1. Glossary

Baseline. The state before the intervention, against which progress can be assessed or comparisons made. Baseline data are usually collected prior to the start of the intervention to assess the before state, or at least at the very beginning of the intervention. The availability of baseline data is important and in planning the evaluation much attention should be paid at this.

Causal attribution. Causal attribution investigates the causal links between a program, policy or intervention and observed changes. Causal attribution is an essential element of impact evaluation. It enables an evaluation to report not only that a change occurred, but also that it was due, at least in part, to the program, intervention or policy being evaluated.

Causal link. The correlation between a factor and an outcome.

Evaluation. A periodic, objective and systematic assessment of an ongoing or completed project, activities, policies, their design, implementation and results. The aim is to determine the relevance and fulfilment of objectives, developmental efficiency, effectiveness, impact and sustainability.

Ex ante impact evaluation. An impact evaluation prepared before the intervention takes place. It predicts the likely impacts of an intervention, program or project to inform resource allocation. Ex ante designs are stronger than ex post evaluation because of the possibility of considering all necessary factors of context, methods and baseline data from both treatment and comparison groups.

Ex post evaluation. An impact evaluation prepared once the intervention has started, and possibly been completed.

Impact. In the context of impact evaluation, an impact is a change in outcomes that is directly attributable to a program, program modality or design innovation. Impact evaluations typically focus on the effect of the intervention on the outcome for the beneficiary population.

Impact evaluation. An evaluation that provides information about the impacts produced by an intervention by understanding the causal link between a program or intervention and a set of outcomes.  It goes beyond looking only at goals and objectives to also examine intended and unintended impacts.
Intervention. It is the focus of the impact evaluation. It can be a program, project, policy to be evaluated.

Mixed methods. The use of both quantitative and qualitative methods in an impact evaluation design.

Monitoring. The continuous process of collecting and analyzing information to assess how well a program, project or policy is performing. Monitoring usually tracks inputs, activities and outputs, only occasionally it includes also outcomes. Monitoring data provide essential information for the evaluation.

Process evaluation. A type of evaluation which examines the nature and quality of implementation of an intervention, program or project. It is done during the implementation and it can use different methods including checking that implementation meets standards, cycles of quality improvement or document innovation.

Theory of Change. A theory of change explains how activities are understood to produce a series of results that contribute to achieving the ultimate intended impacts. It consists of laying out the underlying causal chain linking inputs, activities, outputs, outcomes and impacts, and identifying the assumptions required to hold if the intervention is to be successful. It should be the starting point in every impact evaluation.

Outcome. A result/effect that is measured at the level of program, policy, or project beneficiaries. Outcomes are results to be achieved once the beneficiary population uses the project outputs. The can be affected both by the implementation of a program, policy or project (activities and outputs delivered) and by behavioral responses from beneficiaries exposed to that program, policy or project. An outcome can be intermediate or final (long term). Final outcomes contribute to define the impact.

Output. The tangible products, goods and services that are produced directly by a program, policy or project’ activities. The delivery of outputs is directly under the control of the program implementing actor or consortium. The use of outputs by beneficiaries usually contributes to changes in outcomes.