There are some key distinctions between randomized controlled trials (RCTs) in a psychotherapeutic context and in a medical context. There are key differences between designing an RCT to evaluate a new drug and an RCT to evaluate a new form of couples therapy. However, it is important to begin by defining and understanding the importance of the RCT in research (O'Brien, 2013). O'Brien (2013) defines RCT as a research technique that has spanned the centuries. It was first applied in medical practices. Today it is a quantitative method widely used in clinical studies in which participants answer or confirm a research question. Clinical trials designed with RCTs in a medical context focus on prioritizing the protection of human participants with the help of ethical criteria; however, at the researcher's discretion (O'Brien, 2013). Randomized controlled trials can be used in several types of evaluations, including novel therapies (e.g., cognitive behavioral therapy versus emotion-focused therapy in couples treatment), community interventions, and diagnostic techniques (O'Brien, 2013). The RCT study design randomly assigns participants to an experimental group or a control group. As the study is conducted, the only expected difference between the control and experimental groups is the outcome variable studied (O'Brien, 2013). There are advantages to using RCT, firstly, the effect of using randomisation “wipes out” any population bias and it is easier to ignore observational studies (O'Brien, 2013). The results can be analyzed with reliable statistical tools and participants can be clearly identified (O'Brien, 2013). The disadvantage of this method is that it is often expensive and time consuming. The Journal of Sexual Medicine, 9(12), 3089-3107. doi:10.1111/j.1743-6109.2012.02970.xClinical Research. (2013). TCPS 2: 2nd Edition of the Tri-Council Policy Statement: Ethical Conduct for Research Involving Humans. Retrieved from http://www.ethics.gc.ca/eng/policy-politique/initiatives/tcps2-eptc2/chapter11-chapitre11/Dunne, R.L., Kenardy, J., & Sterling, M. (2012). A randomized, controlled trial of cognitive-behavioral therapy for the treatment of posttraumatic stress disorder in the context of chronic whiplash. Clinical Journal of Pain, 28(9), 755–765. O'Brien, D. (2009). Randomized controlled trials (RCTs). In R. Mullner (Ed.), Encyclopedia of health services research. (pp. 1017-1021). Thousand Oaks, CA: SAGE Publications, Inc. doi: http://dx.doi.org.proxy1.ncu.edu/10.4135/9781412971942