Developing a logic model to guide evaluation of impact for learning disability projects: the case of the Positive Behavioural Support (PBS) Academy

Measuring “impact” is an important aspect of the dissemination of evidence-based practice and relevant to all disciplines. However, it has only recently become a focus of enquiry and is not commonly directly researched within the learning disabilities field. The purpose of this paper is to describe the process of developing a logic model for the UK Positive Behavioural Support (PBS) Academy as part of an evaluation and impact study of its work to date.

Logic models are a visual representation of the relationship between a project’s resources, activities and outputs and identified outcomes, in relation to key stakeholder groups. This representation allows for key impact measures to be identified and can be a useful tool for evaluation purposes. The authors used the process outlined by McLaughlin and Jordan (1998) to develop a bespoke logic model for the PBS Academy.

The model was particularly helpful in making clear the distinction between output and impact, identifying impact criteria differentiated by stakeholder group and across time scales, and highlighting areas of activity that are needed to increase the impact of the work of the PBS Academy in the longer term.

In the absence of any generalised impact evaluation frameworks in the learning disabilities field, the authors suggest that logic models may provide a useful framework for evaluating the impact of policy, practice, and research interventions.