STAGE 6. Defining the evaluation plan

What steps should be completed?

Step 1: Select the type of evaluation


An intervention process is analysed to find out how it has progressed and how the participants assess it. Process evaluation1 estimates achievement (if the planned activities were carried out), coverage (if the target population was reached), accuracy (if the activities were applied according to the proposed plan) and satisfaction of intervention recipients and administrators. It helps to explain the results achieved and to analyse potential improvements to be introduced in future interventions.2

Regardless of the type of intervention performed, you should always evaluate the process. This is especially important in new interventions, very complex ones, ones with little documentation and information about the effects of implementation and ones that target socially disadvantaged population groups. The personal and social characteristics of this type of population often require more adjustments to be carried out, and it is very useful to understand the changes that have been made to incorporate them into future implementations.

Processes can be evaluated in any type of intervention, and this provides valuable information to:

  1. Understand how the intervention has progressed. Evaluating the process provides evidence on the degree to which actions have been implemented and on how successful the intervention has been, allowing elements to be identified that could improve intervention quality and prevent future failures. 
  2. Adjust the intervention during implementation. When information is gathered from participants, adjustments can be made to help improve participant responsiveness and involvement in intervention activities without compromising efficacy. This procedure is comparable to what some evaluation manuals call follow-up or monitoring.
  3. Interpret the results. The effects of an intervention depend to a great extent on how it has been developed. Therefore, the results can only be interpreted properly if the implementation process is understood. For example, an intervention may not achieve results if implementation has been incomplete.
  4. Enable the intervention to be replicated in another environment. Documenting the process of executing an intervention is very valuable to understand what has worked and what has not. Without this information, similar interventions cannot be implemented in other contexts or even in the same region in the future.

Different types of indicators can be used to evaluate the process. +



1 Adapted from Alonso C, Salvador T, Suelves JM, et al. (2004). Prevención de la A a la Z. Glosario sobre prevención del abuso de drogas [Prevention from A to Z. A drug abuse prevention glossary. Madrid: Centro de Estudios sobre Promoción de la Salud.

2 EMCDDA. (2010). Prevention and Evaluation Resources Kit (PERK). Luxembourg: Publications Office of the European Union.