Have you ever learned science outside of school, free of fact-based standards and tests? Were you at a museum, national park, or maybe in front of a TV? Science educators refer to this kind of learning as free-choice learning or informal learning. The terms are often used when talking about institutions such as museums, zoos, and science centers. With summer now upon us—the time of year when we are most likely to visit an informal learning institution—it seems particularly appropriate to introduce this research field.