Since the search for ways to measure the impact of social development work gained an urgency in the mid 1990s, the debate has proceeded in several directions, with various methodologies devised to meet specific requirements. Whilst some would regard the search for ways to measure impact as an extension of the more familiar ways of monitoring and evaluation of a particular intervention – with an emphasis on identifying long-term, sustainable, planned and unplanned changes – others see impact measurement as something rather different. In recent years there has been a trend for the measurement of impact to be seen as more to do with understanding the process of social change at a wider level, in order to inform our practice.
Impact assessment needs to be reclaimed as a tool for making judgments about different approaches to social development. At worst, the current trend for measuring agency wide ‘global impact assessment’ seems to be adapting measurement to serve as a tool for the marketing department – identifying in rather loose ways ‘plausible linkages’ between long-term social change and given interventions. We argue that the need for rigour in our methodology is all-important.