Many theories, methods, and practices are utilized to evaluate teachers with the intention of determining teacher effectiveness to better inform decisions about retention, tenure, certification and performance-based pay. In the 21st century there has been a renewed emphasis on teacher evaluation in public schools, largely due to federal "Race to the Top" funding and the emergence of value-added models for determining teacher performance in relation to student achievement. Bearing that in mind, this study was designed to address the question: Where are the consistency and differentiation among criteria used to measure teacher effectiveness ratings when a 21st century, Race to the Top driven, standards- and teacher-effects-based model (Danielson and McGreal, 2000; Stake, 2006) is compared to a traditional, objectives-based model (Tyler, 1940), using the same population over a single school year, while also using different evaluators for each model? An answer proved to be elusive because almost no variation was discovered in the traditional model data, while no variation was discovered in the 21st century model data. A strong proportion (0.99) of selected scores in both models was discovered, but the lack of variance across all scores limits generalizability to a larger population. The proportion indicates that for the population in this study (n = 80), despite the additional time needed to implement the 21st century model and its higher ordinal scaling, the 21 st century model did not meet its primary goal of better recognizing effective teaching than the traditional model. Changes to the structure and/or implementation may be required for the 21st century model, so that more dispersion can be identified and reported, which will theoretically better inform decisions about retention, tenure, certification and performance-based pay. [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/en-US/products/dissertations/individuals.shtml.]