STAGE 6. Defining the evaluation plan

What steps should be completed?

STEP 1: Select the type of evaluation

Evaluating an intervention means studying it. This study or analysis can performed on various components of the intervention, which gives rise to different types of evaluation. However, One Step@a Time aims to facilitate access to the evaluation practices so, instead of covering all the different possible ways of evaluating an intervention, it focuses on two of them: process evaluation and outcomes evaluation. Both are required to make more complex evaluations, such as of economic impact. The process evaluation and outcomes evaluation provide complementary information and, although sometimes they are confused, their purposes are different and they use different information. The first differences between the two can be illustrated by the following table:




Which drug-related situation do I want to change?

Formulating general objective


Which personal determinants must change to change the behaviour of the target population?

Formulating the specific (personal) objectives


Which environmental determinants must change to change the behaviour of the target population?

Formulating specific (contextual) objectives


How are the personal and environmental determinants going to be changed?

Formulating activities


While the outcomes evaluation focuses on verifying that the general objectives and specific objectives have been achieved, the process evaluation focuses on analysing how the intervention has been implemented, and is therefore based on the action plan.


Therefore, the evaluation keeps a logical connection with the initial tasks of the intervention’s planning process so no particular type of evaluation is better than another, but the most appropriate in each case is the one that is defined according to the objectives, action plan and resources available.


A key task in every evaluation is to select the indicators that will enable the intervention to be analysed. This aspect is reported in step 2 of this stage.

Additional information about evaluation can be found at the following links: See