If your goal is to become a high-level tennis player, then it makes sense to look to high-level tennis players for data on how to achieve that goal: How many hours do they practice each day? How often do they play in tournaments? What kind of cross-training do they do? Which styles are popular in this day and age? And so forth. In the same way, if you’re learning a foreign language, and your objective is to sound like a native speaker, then it makes sense to look to native speakers for data on how to succeed. Or does it? Many people within the language-learning community would push back at this moment, saying that acquiring a native language is a fundamentally different endeavor than acquiring a foreign language. According to such individuals, children and adults are different on a basic neurological level, and therefore what works for children won’t necessarily work for adults. When designing a method for adult acquisition, they say, it doesn’t make sense to look to children for inspiration.