ABSTRACT
Comparative impact analysis seeks to answer the question whether a given programme or type of programme makes a difference to those at whom it is aimed, either in comparison with an alternative service (or range of services) or compared with no provision of any kind. For example, one of the crucial issues for mediation services is how their interventions compare (in terms of
quality of process, outcome etc) with those associated with alternative service providers such as local authority housing and environmental service departments.
