However, the positive effects of CBTraining have been difficult to prove throughout the field of research. Lack of randomized controlled trials (RCTs) in many studies and a lack of a standardization of training methods and definitions of success make it difficult to compare studies with each other and find trends. Overall, many clinical reviews conclude that initial results expressing the benefits of CBTraining may have been overestimated, but the data shows positive enough results that continued research is encouraged.