Background/Context: Since the 1970s, researchers have attempted to link observational measures of instructional process to student achievement (and occasionally to other outcomes of schooling). This paper reviews extensively both historical and contemporary research to identify what is known about effective teaching. Purpose/Objective: Good, after reviewing what is known about effective teaching, attempts to apply this to current descriptions of effective teaching and its application value for practice. Good notes that much of the "new" research on effective teaching has simply replicated what has been known since the 1980s. Although this is not unimportant (since it shows that older findings still pertain to contemporary classrooms), it is unfortunate that research has not moved beyond the relationship between general teacher behavior (those that cut across subject areas) and student achievement (as measured by standardized tests). How this information can be applied and the difficulty in using this information is examined in the paper. Research Design: The paper is a historical analysis and reviews research on teaching from the 1960s to today. Conclusion: This paper has stressed that our data base on effective teaching is limited--still it has some implications for practice. Even though the knowledge base is limited, there is no clear knowledge that teachers-in-training learn and have the opportunity to practice and use. It would seem that teacher education programs would want to assure that their graduates, in addition to possessing appropriate knowledge, would also have clear conceptual understanding and skills related to active teaching, proactive management, communication of appropriate expectations for learning, and the ability to plan and enact instruction that balances procedural and conceptual knowledge. Future research on the use of this knowledge base and its effects in teacher education programs would be informative. If done correctly, research on teaching can improve instruction. However, the research must be applied carefully if it is to have useful effects. And, as noted often in this paper, research must consider outcomes of schooling other than achievement such as creativity, adaptability, and problem finding.