Value+Added+Measures

"Value added measures" (also referred to as "value added measurement" or "value added models" or "value-added metrics") is a concept from education economics that has gained popularity recently in corporate education reform circles. It attempts to measure the "value" that a teacher "adds" to a student over the course of a school year. Typically, standardized test scores are used as the metric for "value added". "Value added measures" then become a tool for evaluating teachers, conveniently reducing what a teacher does to simply improving standardized test scores. In value-added terms, good teachers raise scores, bad ones don't.

Read the Chicago Teachers Union position paper on teacher evaluation, Promoting Quality Instruction: Teacher Evaluation or Teacher Collaboration?

Value added in the news
Tested: Covering schools in the age of micro-measurement - //Columbia Journalism Review//, March-April, 2011. How value-added measures have been covered in the media. Student Test Score Based Measures of Teacher Effectiveness Won’t Improve NJ Schools- School Finance 101 blog by Bruce Baker, 3/13/2011 Evaluating New York Teachers, Maybe the Numbers Do Lie - //New York Times//, 3/7/2011

Resources on value added measures
For a good summary of the problems with using high-stakes tests for evaluating teachers, see "Neither Fair Nor Accurate: Research-Based Reasons Why High-Stakes Tests Should Not Be Used to Evaluate Teachers" by Wayne Au, from the Winter 2010-11 issue of //Rethinking Schools//.

Can Teachers be Evaluated by their Students' Test Scores? Should They Be? The Use of Value-Added Measures of Teacher Effectiveness in Policy and Practice (2010) A report by Sean Corcoran, assistant professor of educational economics at New York York University, for the Annenberg Institute for School Reform at Brown University. "But questions remain as to whether value-added measures are a valid and appropriate tool for identifying and enhancing teacher effectiveness. In this report, I aim to provide an accessible introduction to these new measures of teaching quality and put them into the broader context of concerns over school quality and achievement gaps... Whether or not the shift to intensive use of value-added measures of effectiveness will improve our nation’s system of teaching and learning remains to be seen. Indeed, there are good reasons to believe these measures may be counterproductive."

This is an important research paper from the National Center for Education Evaluation and Regional Assistance, a part of the U.S. Department of Education, by two statisticians with Mathematica Policy Research. Mathematica Policy Research developed the teacher evaluation system used by the Washington, D.C. school district, and which was used to fire teachers there recently. Among other things, the authors findings include:
 * Error Rates in Measuring Teacher and School Performance Based on Student Test Score Gains** (July, 2010)
 * "If only three years of data are used for estimation (the amount of data typically used in practice), Type I and II errors for teacher-level analyses will be about 26 percent each. This means that in a typical performance measurement system, 1 in 4 teachers who are truly average in performance will be erroneously identified for special treatment, and 1 in 4 teachers who differ from average performance by 3 to 4 months of student learning will be overlooked." p. v
 * "These results strongly support the notion that policymakers must carefully consider system error rates in designing and implementing teacher performance measurement systems based on value-added models, especially when using these estimates to make high-stakes decisions regarding teachers (such as tenure and firing decisions)." p. v
 * And this powerful statement: "Our results are largely driven by findings from the literature and new analyses that //**more than 90 percent of the variation in student gain scores is due to the variation in student-level factors that are not under the control of the teacher**//." p. 35 (emphasis added)

A briefing paper from the Economic Policy Institute, co-authored by several scholars convened by the EPI. media type="custom" key="8673440"
 * Problems with the Use of Student Test Scores to Evaluate Teachers**(August, 2010)

What factors affect student learning?
One of the fundamental assumptions of value-added measures is that teachers are single most important factor in student achievement. However, this considers only in-school factors, and even that the relative importance of teacher skill may be overstated. The 30-minute talk below (Flash video) by Richard Rothstein, delivered at a January 19, 2011 symposium on standardized tests and teacher evaluation sponsored by the Educational Testing Service, dissects the narrative around value-added measures and teacher evaluation. See also "An overemphasis on teachers" by Rothstein, from October, 2010.

media type="custom" key="8673406"

//See also Larry Ferlazzo's blog posting, "The Best Places To Learn What Impact A Teacher & Outside Factors Have On Student Achievement"//