This document discusses research on effective feedback and its role in visible learning. It outlines a session on feedback that will cover the background research, an instructional feedback model, and a case study of visible learning in action at George Spencer Academy. Effective feedback can have sizable effects on learning, with some studies finding an effect size of 0.75. The purpose of feedback is to close the gap between a student's current and desired level of understanding. Praise should not be confused with effective feedback.