Alternative medicine practices are as diverse in their foundations as in their methodologies. Practices may incorporate or base themselves on traditional medicine, folk knowledge, spiritual beliefs, or newly conceived approaches to healing.^[8] Jurisdictions where alternative medical practices are sufficiently widespread may license and regulate them. The claims made by alternative medicine practitioners are generally not accepted by the medical community because evidence-based assessment of safety and efficacy is either not available or has not been performed for many of these practices. If scientific investigation establishes the safety and effectiveness of an alternative medical practice, it may be adopted by conventional practitioners.^[9][10] Because alternative techniques tend to lack evidence, some have advocated defining it as non-evidence based medicine, or not medicine at all. Some researchers state that the evidence-based approach to defining CAM is problematic because some CAM is tested, and research suggests that many mainstream medical techniques lack solid evidence.^[11]