Outcome measures relate to the goals of the programs and require multiple measures, including placement, subsequent maltreatment, family problems, and child and family functioning. Outcome measures are the heart of the experiment, but other types of measures were also needed in order to carry out the study and to more fully understand the observed overall impact in specific sites. Other measures include mediating and conditioning variables. Mediating variables reflect intervening factors that may be the underlying mechanism for achieving change in the more general outcomes, including parents’ coping skills, the family’s social isolation or embeddedness, and the general quality of interactions in the home environment. There is not always a clear dividing line between mediating and outcome measures. Moreover, an outcome in one realm may be a mediator in another. For instance, adequacy of the parent’s attention to a child’s health may be considered an outcome as itself, but it is also a key mediating variable in relation to other outcomes. Measures that may “condition” the effects of the treatment, such as demographic and household composition variables, were examined for their potential influence. For example, family preservation services may emerge as more effective for families with certain characteristics (e.g., single parent families, younger children). We also used check measures to ensure that the treatment that was intended actually occurred and to determine whether control group families received services that are supposed to be reserved for members of the experimental group. Finally, the study used service variables to identify at the program level those variables necessary for understanding the results at the family level.