There’s been a noticeable increase in the amount of pedagogical literature that references what’s been documented about learning in cognitive psychology. It seems to be part of the ongoing interest in making instructional practices more evidence-based. But there’s an issue that makes the application of these research findings challenging. Most of the research in cognitive psychology has been done in labs or simulated classrooms. It hasn’t been done in actual classroom and for reasons that make sense. First, classes enroll students who need to take the course. That cohort may or may not be representative of the average classroom—there may be more males than females, more students with high GPAs, more students from a particular major, and any number of other differences with the potential to influence the outcome depending on what’s being studied. Then there’s the very dynamic nature of the classroom. There’s all sorts of variables that are difficult, if not impossible to control. The content isn’t the same, even if the same teacher presents it. The interaction between and among the students can influence what’s learned and how it’s learned. Classroom policies create environments that are experienced differently by students. Compared to what occurs in labs, the learning that happens in classrooms is messy.