External validity. It's a topic that many of us don't really talk about. It's the idea that certain research findings only apply to certain groups. In sleep training, most people assume the research is applicable to all families, but is this the case? This is the question that Dr. Levita D'Souza and I examine this week as we talk about the research that provides us information on who takes part and who doesn't, and what this means for our understanding of the research in broader terms. Dr. Levita D'Souza: https://www.centreforperinatalpsychology.com.au/psychologists/levita-dsouza/ Relevant Research: https://academic.oup.com/sleep/article/43/4/zsz268/5611128?login=false https://publications.aap.org/pediatrics/article-abstract/130/4/643/30241/Five-Year-Follow-up-of-Harms-and-Benefits-of