Great teachers make a profound difference in the lives of children. Each of us can remember the personal qualities of a great teacher whose influence stretches into our adulthood--or who gave our own children a solid start in life. But these elusive qualities are hard to measure. It's even harder to use them to predict who will become a great teacher. In the public school arena, the policies enacted by state governments and local school districts decide who will have access to this honored profession. These policies have a tremendous impact on the quality of the nation's teaching force, making it critical that they are based on the best knowledge available. Otherwise, prospective teachers who might prove to be quite effective are shut out and others who should not be are allowed in. To be fair and practical, these policies must also rely on objective measures of a prospective teacher's strengths. This booklet from the National Council on Teacher Quality (NCTQ) summarizes briefly what the research says about the attributes of an effective teacher. NCTQ has combed through the research, good and bad, to present in plain English, shorn of all statistical jargon, findings that have resulted from well-designed and well-executed studies. It is the authors' firm hope that the information presented here will help policymakers look for new and better ways to improve teacher quality and help schools understand that no regulation, no matter how sound, can replace the critical need for schools to screen prospective teachers carefully. It is the authors' firm belief that well-designed policies based on good research will increase the odds that the individuals who make it through the pipeline will be teachers each of us would want for our own children. (Contains 59 endnotes.)