Providing students with timely and meaningful feedback is an important part of the learning process. In providing formative feedback, it is important that the teacher take the full complexity of the student into account, examining not only what the student learned or failed to learn but also why. There are numerous factors that are associated with why students did learn or fail to learn, and affective and motivational factors are considered especially important. However, these factors are often difficult for teachers to assess in the classroom, and as such can be overlooked in efforts to promote student success. The purpose of this paper is to discuss the need for formative assessments that take affective and motivational factors into consideration. In doing so we introduce a noncommercial tool, the Subtle Stone, that can be integrated into the classroom to make the affective and motivational experience of students more readily available to teachers. We seek to explore whether the addition of such a tool to the classroom can enable teachers to take account of the holistic experience of students in their formative assessment activities.