Categories were defined as follows: programs in the «found to work» category had positive and statistically significant impacts on a particular child or youth outcome; programs in the «mixed findings» category had varied impacts either
on particular outcomes, at different times, or for varied subgroups; and programs in the «not proven to work» category had non-significant or marginally significant impacts on a particular child or youth outcome.
Local program implementation is guided by the direction of the national model developers (HFA and NFP) through the articulation of their service models, including their focus
on particular outcomes and families and their guidelines regarding dosage and delivery of services.