State investment in pre-K programs is predicated on the belief that pre-K is effective at promoting school readiness skills, and, most importantly, that those skills will then be linked to long-term school success, i.e., closing the achievement gap. Oddly, despite huge support for pre-K from politicians and advocates alike, three critical questions related to this belief have not been addressed. The first is which skills and dispositions among young children are the most important to influence early for long-term success in school. The second is which classroom and center practices will work to promote those skills and dispositions. The final question is which assessment systems will validly capture the quality of those practices when they are scaled up for delivery in thousands of pre-K settings. In this paper, I argue that essential research to answer those questions has not yet been done. (author abstract)