Promoting the idea that teachers can make sophisticated diagnostic judgments and can identify appropriate instructional techniques, this book delineates the process of diagnostic teaching so that teachers can make such judgments and identify such techniques. The book is designed to supplement course work in the diagnosis and remediation of reading difficulties. The instructional techniques in the book are written in a step-by-step fashion so that classroom teachers and practicum students can readily follow the prescribed procedures. Chapters in the book are: (1) What Is Diagnostic Teaching?; (2) The Reading Event; (3) Roles of Diagnostic Teachers; (4) The Diagnostic Teaching Session: An Overview; (5) Gathering Diagnostic Data; (6) Formulating Diagnostic Hypotheses; (7) Assessment Using Diagnostic Lessons; (8) Assessment Using Portfolios; (9) Selecting Techniques; and (10) The Instructional Techniques. Contains approximately 200 references. An appendix on administering an informal reading assessment is attached. (RS)