Although science has provided empirical evidence for centuries, it's only as recently as the 1940s that a scientific method called randomized controlled trials (RCT) emerged as a technique to test the efficacy of drugs and medical procedures. Since RCT is unique in that it can claim causality, it's considered the "gold standard" of research because it yields the most reliable evidence. In this article, the author argues that the issue isn't whether the gold standard generates the most reliable evidence. It's whether it is the "only" way to determine what works. The Italian physician and educator Maria Montessori developed her model of schooling through observation and documentation. The powerful theory of learning called constructivism originated with the work of Jean Piaget, the Swiss psychologist who observed and chronicled the development of his young daughters. Constructivism was behind many of the 20th century's most prominent educational theories--from John Dewey's child-centered, hands-on approach to learning to library researcher Carol Kuhlthau's theory of "zones of intervention," which articulates how information seekers move from uncertainty to understanding. The generalizability of this research is in its cumulative effect: the resulting body of knowledge is a virtual gold mine that's still yielding effective educational practices. The author further contends that no matter how rigorous gold-standard research is, when applied to educational research, it's not the silver bullet that's going to lead to the "right" answer.