The document discusses the skill of explanation in teaching. It defines explanation as showing relationships among concepts, ideas, events or phenomena. Explanation involves selecting appropriate statements to interrelate ideas and using those statements to bring about understanding. Good explanation skills include using an introductory statement, concluding statement, explaining links, and testing student understanding, while undesirable behaviors involve irrelevant statements, lack of continuity or fluency. The document also categorizes explanations as interpretive, descriptive or reason-giving and provides guidance on developing explanation skills.