This study investigated the factors that affect the impact of an intervention programme for parents of five and six year olds, and was called the Primary Age Learning Study (PALS). The aims of this study continue the tradition of other studies published by the Joseph Rowntree Foundation (JRF) on related topics, including recently Routes out of Poverty: A Research Review (Kemp et al. , 2004), Migration and Mobility: The Life Chances of Britain?s Minority Ethnic Communities (Platt, 2005) and Anti-social Behaviour Strategies: Finding a Balance (Millie et al. , 2005). However, while most JRF studies are observational, this study is one of the few that is an evaluation of an intervention; for example, it follows the evaluation of three ?Communities that Care? demonstration projects (Crow et al ., 2004). It is only the second we know of that is a randomised controlled trial, which is by far the surest way to determine effectiveness; the other was the study of the outcomes and costs of Home-Start support for young families under stress (McAuley et al. , 2004). The support given in Home-Start was very well received by parents, although it did not show any impact on parenting or child outcomes during the time period of the study.