The mission statement of the American Educational Research Association (AERA) articulates the following goals: "improving the educational process," "advancing knowledge about education," "[encouraging] scholarly inquiry related to education," and "[promoting] the use of research ... to serve the public good." I examine AERA presidential addresses from 1948 to 2010 as windows into how the research community has conceptualized learning and explore the following questions: (a) What has evolved in the science of learning? (b) With what persistent questions has the field wrestled? (c) In what ways has the field addressed broader factors--social, cultural, political, economic--that represented the ecological contexts in which education in formal and informal settings played out in each decade?