%0 Journal Article
%T Value-Added Modeling of Teacher Effectiveness: An Exploration of Stability across Models and Contexts Modelos de Valor A adido de la eficacia docente Modelos de Valor Agregado da Efic¨¢cia Docente
%A Xiaoxia A. Newton
%A Linda Darling-Hammond
%A Edward Haertel
%A Ewart Thomas
%J Education Policy Analysis Archives
%D 2010
%I 
%X Recent policy interest in tying student learning to teacher evaluation has led to growing use of value-added methods for assessing student learning gains linked to individual teachers. VAM analyses rely on complex assumptions about the roles of schools, multiple teachers, student aptitudes and efforts, homes and families in producing measured student learning gains. This article reports on analyses that examine the stability of high school teacher effectiveness rankings across differing conditions. We find that judgments of teacher effectiveness for a given teacher can vary substantially across statistical models, classes taught, and years. Furthermore, student characteristics can impact teacher rankings, sometimes dramatically, even when such characteristics have been previously controlled statistically in the value-added model. A teacher who teaches less advantaged students in a given course or year typically receives lower effectiveness ratings than the same teacher teaching more advantaged students in a different course or year. Models that fail to take student demographics into account further disadvantage teachers serving large numbers of low-income, limited English proficient, or lower-tracked students. We examine a number of potential reasons for these findings, and we conclude that caution should be exercised in using student achievement gains and value-added methods to assess teachers¡¯ effectiveness, especially when the stakes are high. El reciente inter¨¦s para relacionar los resultados de los aprendizajes de los estudiantes con las evaluaciones docentes ha provocado un uso creciente de M¨¦todos de Valor A adido (MVA) para evaluar incrementos en los aprendizajes de los alumnos.  Los an¨¢lisis MVA se basan en hip¨®tesis complejas acerca del papel que desempe an las escuelas, los profesores, las aptitudes de los estudiantes, sus esfuerzos, sus hogares y familias en la producci¨®n de incrementos medibles de  aprendizaje estudiantil . Este art¨ªculo discute los an¨¢lisis que examinan la estabilidad de las clasificaciones de eficacia de profesores de escuelas secundarias a trav¨¦s de diferentes condiciones. Encontramos que valoraciones de la efectividad docente de un profesor/a  pueden variar substancialmente a trav¨¦s de los distintos modelos estad¨ªsticos, las clases ense adas y los a os de experiencia. Adem¨¢s, las caracter¨ªsticas de los estudiantes pueden impactar dr¨¢sticamente las clasificaciones de los profesores, a¨²n cuando tales caracter¨ªsticas hayan sido previamente controladas estad¨ªsticamente en un MVA. Los profesores que ense an a los estudiantes
%K teacher evaluation
%K value-added modeling
%K teacher effectiveness
%U http://epaa.asu.edu/ojs/article/view/810