Research investigating why learning to teach is difficult is considered, along with examples that illustrate the issues. A Stanford University study sought to understand difficulties in transforming knowledge to teaching. An example is that some literature classes teach social criticism as well as literature. Some novels also deal with typical problems like individuality and personal development issues, and English teachers also have to teach writing and usage as well. Stanford University's teacher education program is developing uses for case studies of teaching in a manner analogous to the ways business and law schools use them. Examples are cited about how learning from experience for teachers is not simple and does not occur automatically. Effective techniques used by teachers of content courses have been cited as sources of learning to teach by student teachers. A program leading to a teaching degree at Stanford University emphasizes observation by undergraduates of effective methods used by their teachers. (SW)