From a sociocultural perspective to assessment, this study investigated parents' beliefs about formative assessment. When North Carolina (NC) received an Early Learning Challenge Grant, its Department of Public Instruction was funded to develop a kindergarten entry assessment. The department proposed the development of a kindergarten to third grade assessment that was formative in nature and could be conducted in the context of teaching and learning. Formative assessment is an alternative to large-scale assessment providing a broader picture of children's learning and effectively informing teachers' future instructional process. The present study explored parents' general beliefs about formative assessment and parents' attitudes toward strategies for obtaining family information relevant to this assessment. A total of 152 parents of children attending kindergarten to third grade in eight NC school districts participated in focus groups. Results revealed parents desired to receive more information about their children's learning, behavior, and interests so they could support their children at home. Parents also emphasized the importance of the form in which information about their child is conveyed. Finally, parents demonstrated their willingness to provide information about their child's development and learning at home and to be co-interpreters of the child's participation in school. Findings underscored the critical importance of parents' contributions to understanding children's transformation in school and that assessments that are co-designed and co-interpreted with parents can provide evidence that can deliver meaningful improvement to educational practice.