Over the last decade much attention has been directed to the need for the public to benefit from medical and behavioral research. The recognized importance of moving scientific discovery to clinical and public health practice has inspired countless publications and serves as the foundation for the National Institutes of Health (NIH) Roadmap Initiative.1, 2, 3 “Translation Research” can be categorized into “Translation 1” activities (developing and determining the efficacy of interventions derived from more basic biomedical, behavioral or epidemiologic discovery) and “Translation 2” activities (bringing efficacious programs to practice).4, 5 Under this broad mandate, Translation 2 activities include at least two phases: 1) further effectiveness trials of efficacious interventions; and, 2) the diffusion (defined as the uncontrolled or natural spread of innovations), dissemination(defined as purposeful or deliberate efforts to move an innovation) and implementation (defined as adoption or utilization of the innovation) of efficacious programs that may or may not have been further validated as effective6, 7, 8. Pediatricians may be interested and/or involved in many aspects of translation research depending on the nature of their practice, but all will be involved to some degree in implementation, whether as a researcher, a health care provider, or both. While probably aware of the importance of implementation of new advances in health care, many clinicians may not be aware of the issues encountered in this final and critically important step of the research chain. Until recently, implementation generally had been conceptualized as the final step of the broader processes of diffusion or dissemination, typically had not been the primary focus of the research or field activity6, 7, 9 and had received little attention during medical school or residency. Implementation of an effective intervention, whether a procedure, a medication, a device or a program designed to change, prevent or reinforce a behavior (behavioral intervention), requires focused attention on identifying exactly what aspects of the intervention have contributed to efficacious outcomes and therefore need to be retained in subsequent implementations to disparate audiences. While it may seem logical that to retain its effectiveness an intervention must be implemented (reproduced) “exactly as it was” when it was demonstrated to be effective, clinicians and scientists have come to realize that often it is not clear what it means to reproduce an intervention “exactly like it was” when it was demonstrated to work. Key questions for the implementation component of translational research are: What occurs in practice when a new product or intervention is introduced? What is (are) the critical components of the intervention that resulted in effectiveness?; and, What factors are related to increased fidelity? Addressing these three questions about any intervention that has been shown to improve health outcomes under different conditions is complex; the process is particularly vexing with regard to interventions that are largely or exclusively behavioral in nature, as is the case for many prevention programs, adherence programs, etc. Behavioral interventions frequently involve multiple sessions delivered by interventionists with different levels of training and experience and differing personality and communication styles. Whereas quite specific requirements and procedures have been established for defining the safe and effective regiments for delivery of new medications, vaccines and medical devices by regulatory organizations such as the Food and Drug Administration10, the process for defining safe and effective behavioral interventions has not been subject to the scrutiny and rigor. Effective behavioral interventions have been developed that address important pediatric public health issues including obesity treatment and prevention11, medication compliance12, violence, pregnancy and STD prevention13, and responding to bullying14; lagging behind is guidance to pediatricians regarding their implementation in a manner that will retain their effectiveness. Accordingly, for the remainder of this paper we shall discuss the important area of implementation by addressing the three questions noted above and with a particular focus on interventions that are behavioral in nature. What occurs in practice when a new product or intervention is introduced? There is ample documentation that effective biomedical interventions are delivered in a practice (as opposed to a research) setting, they generally are not delivered as they were under the research conditions when they were found to be effective15. For example, an estimated two-thirds of Americans who are prescribed medications fail to take some or all of the medication16. This simple, common occurrence, well known to most clinicians, illustrates many of the issues confronted in implementing medical innovations. Determining whether in fact a patient has been compliant with a medication prescription is not necessarily straight forward. Besides the basic question as to whether the medication was taken at all, what additional parameters must be met for a patient to be “compliant”? If the patient takes a medication one hour late, is he still compliant?; if yes, then what about two hours late? If in a 10-day course of medication the patient misses one dose, is she compliant? Does it matter of the missed dose was on day 2 versus day 9? Do these variations from protocol reflect a lack of compliance on the part of the physician; that is, did the physician describe exactly when the medication should be taken, ascertain whether or not the patient understood, and assess the issues that the patient saw that might make following this regiment difficult? As complex as assessing the adequacy of adherence to a medication prescription (a largely biomedical intervention) may be, it may be even more difficult to assess adherence to an intervention that is primarily behavioral. First, the process for defining the parameters of the effective intervention that is to be replicated has not been well delineated; that is, how do we decide what part or parts of a behavioral intervention need to be identical in order to represent a “replication” rather than a “reinvention” (or adaptation) of a previously successful intervention? A vast if not universal experience in the implementation of previously developed behavioral interventions is that new “adaptations” or “reinventions” will occur during the implementation of the intervention in a new setting. For example, a process and outcome evaluations of a crime prevention program, “Community Works” conducted across 14 schools found that only 16% of the sessions were delivered “with a high degree of fidelity”, defined as “delivered in a manner intended by program developers”17 page 725. They observed that the majority of the curricular changes appeared to be dictated by local needs and resources. Further, the authors suggested that some changes are needed and recommend that program developers should articulate “acceptable degrees of variation”, although this is not further specified.17, p. 735 The recognition that behavioral interventions are changed as they are implemented is not new. A Rand report issued in the 1970’s entitled “Implementation of Educational Innovation” found that among a representative sample of US teachers, 79.8% reported adapting their prevention curricula18. Indeed, a vast literature exists on the phenomenon of local change to interventions. Whether it is called “adaptation”, “reinvention”, “cultural adaptation” or “culturally appropriate modification,” all of the terms acknowledge that some change appears to part of the process of implementation of interventions18-23.