Assessment for learning (AfL) has become a widespread approach across many educational systems. To date, AfL research has emphasized teachers' knowledge, skills, and practices, with few studies examining students' responses to an AfL pedagogical approach. The purpose of this research was to focus directly on students' perspectives on their use and value of AfL approaches through a survey of 1079 K-12 students and portfolio-based interviews with 12 purposefully selected students. Survey data were analyzed through descriptive and inferential statistics across grade levels. Interview data were analyzed using standard thematic coding processes. Students most frequently used and valued teacher feedback and success criteria to support their learning. Peer feedback was the least valued AfL approach for all students. Some significant differences between grade levels were noted. Our results suggest that using AfL approaches is a learned behaviour; students need to be explicitly taught about AfL concepts, terminology, and use over time. This study also highlights that AfL implementation requires sustained focus, research, and support in schools and classrooms for students to value and fully benefit from assessment-based teaching.