A great deal of teacher planning involves an invisible process of envisioning how plans might unfold in the classroom. Novice teachers can benefit from seeing how experienced teachers work through this process, but, too often, co-planning sessions between mentors and novices focus on selecting activities to fill out a lesson, rather than delving into the reasons for those choices. Stacey Pylman recommends that mentors make their co-planning sessions into a time for novices to learn. As a reminder of the elements of an effective planning session, she offers the acronym ICEBERG: Intentionally prepare, Clarify content, Explain why, Break for questions, Envision aloud, Return to the objective, and Gradually release decisions.