There is a great deal of concern regarding teacher impacts on student achievement being used as a substantial portion of a teacher's performance evaluation. This study investigated the degree of concordance and discordance between mathematics teacher ranking using value tables and covariate regression, which have both been used as measures for teacher effectiveness. The researcher examined teacher rankings, before and after the state recommended classification, using correlational techniques, comparison matrices, and visual examination for value-added scores derived from the value table versus the covariate regression approach. Examination demonstrated strong correlations between the initial rankings (r = 0.77 to 0.98) and a high concordance (? = 0.96 to 1.0) once the recommended classifications were applied to the teachers rankings. The overall implications of this project are that more complex methods may parse the impact information out with higher statistical accuracy, however, once the recommended classification is applied to the methods there may be very little difference in the classification of teachers. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]