Assessment of Online Learners offers essential foundations, insights, and real-world examples for preservice teachers preparing to assess students in today's digitized classrooms. When aligned with intended curricula and best practices, assessment not only informs but enhances both instruction and student achievement, though the recent large-scale adaptation of face-to-face learning to online platforms has yielded new challenges and responsibilities for teachers. This book explores shifts in the research and practice of assessment in online environments, the reconceptualization of course content and assessment frameworks in teacher education, the collection of fair and accurate assessment evidence reflecting students' virtual learning, and more. Drawing from experienced Canadian instructors who overcame the inherent technological obstacles, these chapters showcase how unprecedented changes in schooling can lead to pedagogical renewal, program reevaluation, and a broader understanding of instruction and assessment practices.