Engagement is one of the most widely misused and overgeneralized constructs found in the educational, learning, instructional, and psychological sciences. The articles in this special issue represent a wide range of traditions and highlight several key conceptual, theoretical, methodological, and analytical issues related to defining and measuring engagement. All the approaches exemplified by the contributors show different ways of conceptualizing and measuring engagement and demonstrate the strengths and weaknesses of each method to significantly augment our current understanding of engagement. Despite the numerous issues raised by the authors of this special issue and in my commentary, I argue that focusing on process data will lead to advances in models, theory, methods, analytical techniques, and ultimately instructional recommendations for learning contexts that effectively engage students.