In discussions about relationships between research and pedagogy, teachers and researchers are often characterized as facing each other across a "gap" that separates them. Teachers are described as having practical concerns about their own classrooms and little patience for "theoretical" issues. Researchers are described as removed from day-to-day classroom concerns and oriented to more abstract factors that, if not "universal," are at least "generalizable." In reality, many researchers share with teachers the goal of making teaching and learning as successful as possible. What they learn from each other can help them reach that goal. In this article, we discuss 3 guiding principles that help to create the conditions for productive collaboration: (a) build trust and long-term relationships, (b) build and share knowledge, and (c) follow up and provide feedback. We describe how the cycle of observation, correlation, and experimentation influenced our research and created opportunities to investigate questions that were of interest to us as researchers and relevant to teachers' goals. We use examples of our own studies and those of other researchers who have engaged in long-term teacher-researcher collaborations, illustrating how the research-pedagogy link can be strengthened.