prospects from the use of the intervention, and how far the intervention is from achieving a goal or an objective. Indicators are used to assess whether progress has been made toward achieving specific outcomes. An outcome is the extent of change in targeted policies, institutions, environments, knowledge, attitudes, values, dietary and physical activity behaviors, and other conditions between the baseline measurement and measurements at subsequent points over time.
Evaluations can range in scope and complexity from comparisons of pre- and postintervention counts of the number of individuals participating in a program to methodologically sophisticated evaluations with comparison groups and research designs. All types of evaluations can make an important contribution to the evidence used as the basis on which policies, programs, and interventions are designed. A major purpose of this Institute of Medicine (IOM) report is to encourage and demonstrate the value for conducting an evaluation of all childhood obesity prevention interventions. The committee strongly encourages stakeholders responsible for childhood obesity prevention policies, programs, and initiatives to view evaluation as an essential component of the program planning and implementation process rather than as an optional activity. If something is considered valuable enough to invest the time, energy, and resources of a group or organization, then it is also worthy of the investment necessary to carefully document the success of the effort. The committee emphasizes the need for a collective commitment to evaluation by those responsible for funding, planning, implementing, and monitoring obesity prevention efforts.
Evaluation is the critical step in the identification of both successful and ineffective policies and interventions, thus allowing resources to be invested in the most effective manner. Because sufficient outcomes data are not yet available in most cases to evaluate the efficacy, effectiveness, sustainability, scaling up, and systemwide sustainability of policy and programmatic interventions, the committee uses the term promising practices in this report to refer to efforts that are likely to reduce childhood obesity and that have been reasonably well evaluated but that lack sufficient evidence to directly link the effort with reducing the incidence or prevalence of childhood obesity and related comorbidities. They are not characterized as best practices, as they have not yet been fully evaluated. Furthermore, the term best practices has inherent limitations in the conceptualization and application to health promotion and health behavior research. Green (2001) suggests that clinical interventions are typically implemented in settings with a great deal of control over the dose, context, and circumstances. The expectation that health promotion research will produce interventions that can be identified as best practices in the same way that medical research has done with efficacy trials should be replaced with the concept of best practices for the most appropriate interventions for the setting and population. Thus, best