An important part of raising the level of rigor in a classroom and school is collaborating with other teachers. There are various options and purposes for working together. Many teachers are members of professional learning communities (PLCs). There are three defining characteristics of PLCs. First, professional learning communities are focused on student learning. Next, there is a culture of collaboration among the participants. Finally, professional learning communities focus on results, no matter what it takes. There are five types of activities PLCs can use to impact student learning: learning walks; lesson studies; charette; technology-based options; and discussions. The bulk of time in a professional learning community is spent simply discussing topics and issues. Most discussions fit in three categories: focus on instruction; focus on assessment; and focus on student results.