The document outlines the stages of planning a PYP unit using the "Bubble Planner". It includes 9 stages: 1) identifying the central idea and transdisciplinary theme; 2) key concepts, lines of inquiry, and driving questions; 3) assessing prior knowledge and student learning; 4) learning activities; 5) resources; 6) evaluating student understanding; 7) inclusion of PYP elements; 8) improvements; and 9) successful experiences. The planner is used to ensure PYP units incorporate essential elements like conceptual understanding, skills development, and learner profile attributes.