Student learning objectives (SLOs) are a set of goals that measure achievement of student growth targets. SLOs require teachers to review content standards and define a big idea (i.e., learning goal) that is central to a discipline. The big idea should be critical for students to learn and to use in subsequent grades. Using the big idea, teachers develop a trajectory-based SLO that describes a continuum in which critical content and skills grow in sophistication over time so that teachers have specific skills they can target as the growth goal of the SLO. Once the trajectory is established, assessments are developed, or selected, to gather evidence about a student’s current stage in the trajectory and to facilitate learning opportunities for students to learn those skills.