The purpose of this phenomenological qualitative study is to describe secondary educators' experiences in planning and implementing formative assessment in rural southern Maryland to gain an understanding of their definition and use of Assessment for Learning (AfL) in diverse classrooms. The theory guiding this study, the sociocultural learning theory, grew from the work of the psychologist Vygotsky. The sociocultural learning theory is the best worldview for this study as Vygotsky's beliefs of parents, caregivers, peers, other mentors (teachers), and culture are responsible for the development of cognition and higher-order functions with learning occurring by interacting with other people. Four essential research questions focus on secondary teachers in a rural school district in Southern Maryland descriptions of and experiences with formative assessment. Data collection for this study includes a questionnaire and interviews using researcher-designed questions conducted with a purposeful sampling of secondary teachers who have experience with the use of formative assessment and journals kept by the same teachers. Analysis of the data includes phenomenological reduction, horizontalization, and clusters of meaning for synthesis. The results explain the how the formative assessment process is used by the chosen educators in secondary classrooms including themes related to their experiences, impact on student learning, and barriers to implementation of formative assessment. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]