Douglas N. Harris
Daniel F. McCaffrey
Stephen W. Raudenbush
A synthesis of the key takeaways from the Carnegie Knowledge Network and recommendations from the Carnegie Panelists.
KNOWLEDGE BRIEF 15
by Stephen Raudenbush
Student scores on standardized tests are used as measures for teacher accountability, but, arguably, helping children score well on an achievement test is of little value in itself. The question is whether a test score gain in a given year of schooling represents growth in skills that matter over the long term. In this brief, Raudenbush reviews the research on the relevance of a teacher’s value-added to lasting cognitive and non-cognitive skills that help prepare students for success later in life.
KNOWLEDGE BRIEF 14
by Daniel M. McCaffrey
Students with disabilities account for about 14 percent of all students in the U.S. These students contribute to the value-added of both special education teachers and many general education teachers, but we know little about how accommodations in instruction and assessment for them affect their teachers’ value-added scores. This brief discusses the factors that may influence value-added for teachers of students with disabilities, and explores the implications of controlling for student disability status when estimating value-added.
KNOWLEDGE BRIEF 13
by Susanna Loeb
In an effort to improve educational outcomes, states and districts across the country are collecting value-added measures to assess the quality of their teachers. The usefulness of value-added measures can only be assessed by how they are used in practice. This brief explores the research on how these measures can best be used to enhance teacher improvement.
KNOWLEDGE BRIEF 12
by Dan Goldhaber
Teacher training programs are increasingly being held under the microscope. Policymakers are beginning to adopt the use of student growth measures to measure the performance of teacher preparation programs. In this brief, Goldhaber discusses what research can tell us about the usefulness of value-added for assessing the quality of teacher preparation programs.
KNOWLEDGE BRIEF 11
by Douglas N. Harris
States and districts across the country are using multiple measures to make personnel decisions about teachers based on a weighted average of the separate measures. This method has strengths and weaknesses. Most discussions of measures of teacher performance measures focus on validity and reliability; but fairness, simplicity, and cost should also be considered.
KNOWLEDGE BRIEF 10
by Stephen Raudenbush
Statistically, comparisons of teachers across different schools make less sense in districts with high levels of between-school segregation.
Much of the research on the validity of value-added for teacher evaluation has been based on studies of its use to rank teachers within the same school. However, most districts are using value-added to rank teachers across the district, and in districts that reflect neighborhood residential segregation, value-added rankings will compare teachers who teach very different types of students. To try to correct this by statistically controlling for school context variables will produce bias so long as the effectiveness of the teacher is associated with attributes associated with the effectiveness of the school.
KNOWLEDGE BRIEF 9
by Susanna Loeb and Jason A. Grissom
As policymakers begin to consider how to use test scores to assess principals, they should be guided by an understanding of how principals influence student outcomes. Value added measures provide information about how schools are doing, but they may not be convincing measures of the causal effect of the principal of student learning.read more »
KNOWLEDGE BRIEF 8
by Daniel McCaffrey
A teacher’s value-added can depend on the test used to assess his or her students’ achievement. Questions about the effect of a test on a teacher’s value-added are particularly salient today because most states will soon be adopting new tests aligned with the Common Core State Standards. Research and past experience suggests that teachers should be prepared for greater year-to-year variability in their value-added ranking for a few years after the change when districts use both old and new tests for value-added calculations.read more »
KNOWLEDGE BRIEF 7
by Douglas N. Harris
Value-added methodology is being applied to the evaluation of teachers in tested grades and subjects, but the vast majority of the research on value-added measures focuses on elementary schools only. Secondary grades differ from elementary grades in ways that are meaningful for the validity and reliability of value-added measures for secondary teachers. Middle and high school teachers have more students, which increase reliability of value-added scores, but this advantage is offset by tracking, which reduces reliability at those grade levels.read more »