Although there is much scientific research available to guide educational decision making, decision making based on prevailing conventional wisdom continues. Five areas are conspicuous for relying on this type of decision making. First, grade retention has been shown in over 600 studies to be detrimental to the child, yet the conviction persists that a child who has not performed well in first grade should be retained. Second, if teachers have the knowledge and students want to learn, common sense would dictate that teachers should talk all the time and have the student remain silent, but over 500 studies show that total student silence is not the optimum method for learning. Third, a longer school year is assumed to be better, yet standardized tests are given in March or April, the time of peak student performance. Fourth, more rules are assumed to be better, yet studies on classroom management show that the optimum number of rules to be announced and enforced is five to seven. Finally, the teaching profession has been through the alternative certification cycle over and over when teacher demand exceeds teacher supply. Over time a concentration of teachers without pedagogical training has proved to be detrimental, yet alternative certification practices continue. (LL)