Advocacy for academically based teacher education informs this article, which stresses the need for persuasive evidence of its value. A summary of the current state of the evidence is presented, concluding that positive evidence is now very limited. What is needed to make the case for academically based teacher education is quantitative empirical evidence. The data presented by Coleman are described as a case study to demonstrate the difficulties in interpreting empirical data developed through quantitative methods. The recent assembling of comprehensive longitudinal databases of student achievement in multiple knowledge domains linking individual students with specific teachers is shown to be a promising improvement available to contemporary researchers. Good data and the means for working with them are currently at hand. Those who support the aims of academically based teacher education are called to develop quantitative empirical arguments that will build a dossier of persuasive evidence on its behalf.