The past two decades have seen a rise in use of term practice' and a simultaneous increase in variations in its definition and evaluation. Some of variability may be attributed to differing, but related, conceptualizations of what constitutes an evidence-based practice across disciplines. Review of literature reveals that a wide variety of professions and professional organizations are wrestling with this topic area. Such disciplines include, but are not limited to, medicine, clinical psychology, school psychology, counseling, behavior analysis, education, and nursing (Kazdin, 2006). Using our backgrounds as an example, it is clear that we--like many of readers of Journal of Early Intensive Behavior Intervention--have training and experience that involves numerous disciplines. Specifically, we both received training in experimental psychology before entering a school psychology doctoral program where we were intertwined in both regular and special education. We were fortunate to receive additional training in a clinical psychology internship and have worked in early intervention settings, school-aged programs, and with adults receiving residential services. In addition, we are also Board Certified Behavior Analysts. Thus, for demonstration purposes, we focused our attention to our governing organizations for insight and clarification regarding evidence-based practices. The National Association of School Psychologists' (NASP) Professional Conduct Manual states that school psychologists are expected to engage in services which are delivered following completion of a strategic planning process based on needs of consumers and an empirically supported program evaluation model (NASP, 2000, pg. 51). Moreover, federal regulations now mandate use of based in selection and design of instructional strategies (Individuals with Disabilities Education Improvement Act of 2004; No Child Left Behind Act of 2001). The American Psychological Association (APA) Presidential Task Force on Evidence-Based Practice--which evolved from an APA Division 12 (Clinical Psychology) Task Force--defines evidence-based practice in its position paper as the integration of best available research with clinical expertise in context of patient characteristics, culture, and preferences (APA, 2006, p. 273). Finally, as Board Certified Behavior Analysts, we operate under Behavior Analyst Certification Board Guidelines for Responsible Conduct for Behavior Analysts which explicitly states that a behavior analyst responsibility to recommend scientifically supported most effective treatment procedures. Effective treatment procedures have been validated as having both long-term and short-term benefits to clients and society (BACB, 2004, Section 2.09a). Although these guidelines may imply a united front across disciplines with regards to an interest in utilizing treatments that work, implementation is a challenge since these terms are too vague to actually prescribe criteria to one's practice. Within broader scope of psychology and education, various other groups are attempting to delineate evidence-based practices further. For instance, both Divisions 17 (Society of Counseling Psychology) and 29 (Psychotherapy) of APA have established task forces to arrive at standards of evidence-based practice (APA, 2006). The Society for Behavioral Medicine has also established similar criteria (Davidson, Trudeau, Ockene, Orleans, & Kaplan, 2003). In addition, Council for Exceptional Children (CEC) called upon its Professional Standards & Practice Committee, as well as its Division for Research, to make proposals for evidence-based practice criteria (CEC, 2006). Finally, Association for Behavior Analysis International recently launched Evidence-Based Practices Special Interest Group (EBP SIG) aimed at translating behavioral research to practice in an effort to provide evidence-based practices to general public. …