The document outlines characteristics of marginal teachers such as a lack of planning, classroom management issues, poor teaching skills, and deficiencies in subject matter knowledge. It provides steps principals should take to assist marginal teachers which include identifying specific areas for improvement, creating timelines and expectations, documenting progress, and providing intensive assistance such as frequent observations, additional training, and observations of master teachers. If improvement is not shown, the final phase involves potential decision making regarding the teacher's employment.