Defining Mathematics Education: Presidential Yearbook Selections, 1926-2012 includes an introduction from Francis (Skip) Fennell, a past president of NCTM, and features nineteen chapters from previous yearbooks, each recommended by a past NCTM president for its enduring quality and relevance. Like the yearbooks they are drawn from, these chapters tell the story of the critical issues, challenges, and innovations that mathematics educators have faced over the past eight decades.This Seventy-fifth Yearbook is a celebration and reflection of the history of the NCTM yearbooks as a great resource on the key issues of mathematics education through the years. The first yearbook, A General Survey of Progress in the Last Twenty-Five Years, was published in 1926, just six years after NCTM's founding. Since then, NCTM yearbooks have consistently focused special attention on a wide spectrum of topics of current or future interest to the professional community of mathematics educators. This book will be the last volume in an exceptional series and is a reflection of where we have been, where we are now, and where we are going.