Recent research has documented the importance of teachers to student achievement, and many factors, ranging from teachers’ verbal ability to their subject matter preparation, contribute to teacher effectiveness.  Demographic changes and new policies, such as class size reduction, have increased the demand for new teachers.  Along with the demand for new teachers is a need to better understand effective teacher preparation programs that encourage individuals to enter teaching and provide the skills new teachers need to succeed in the classroom.

Our research in this area is ongoing.  We analyze the various pathways into teaching in New York City schools to identify the characteristics of teacher education programs that contribute to student learning and achievement.  We examine the choices individuals make in selecting their pathway into teaching and how the various pathways intersect with the schools in which they first teach.  We ask and answer the question: “How do the achievement gains of students differ by the teaching pathway of their teachers?” 

Teacher Layoffs:  An Empirical Illustration of Seniority v. Measures of Effectiveness.  July 2010.  Donald Boyd, Hamilton Lankford, Susanna Loeb, and James Wyckoff.

Today, the financial imbalance in many school districts is so large that there is no alternative to teacher layoffs.  In nearly all school districts, layoffs are currently determined by some version of teacher seniority.  Yet, alternative approaches to personnel reductions may substantially reduce the harm to students from staff reductions relative to layoffs based on seniority.  This policy brief illustrates the differences in New York City public schools that would result when layoffs are determined by seniority in comparison to estimated teacher value-added for fourth and fifth grade teachers employing math and ELA student achievement. We find the differences between seniority and value-added based layoffs are larger and more persistent than we anticipated.  However, as a result of the limited applicability of teacher value-added measures to the full population of teachers as well as concerns about potential mis-measurement of effectiveness associated with using value-added measures even when available, neither seniority nor measures of value-added to student achievement should be the sole criterion determining layoffs.  But ignoring effectiveness measures completely as seniority-based systems do, is also problematic. Instead, the use of multiple measures of effectiveness for layoff decisions holds promise for softening the detrimental effect of layoffs. Policy Brief

Measure for Measure: The Relationship between Measures of Instructional Practice in Middle School Language Arts and Teachers' Value-Added Scores.   May 2010.  Pamela Grossman, Susanna Loeb, Julia Cohen, Karen Hammerness, James Wyckoff, Donald Boyd, and Hamilton Lankford.

Even as research has begun to document that teachers matter, there is less certainty about what attributes of teachers make the most difference in raising student achievement. Numerous studies have estimated the relationship between teachers' characteristics, such as work experience and academic performance and their value-added to student achievement; but, few have explored whether instructional practices predict student test score gains.  In this study, we ask what classroom practices, if any, differentiate teachers with high impact on student achievement in middle school English Language Arts from those with lower impact.  In so doing, the study also explores to what extent value-added measures signal differences in instructional quality.  Even with the small sample used in our analysis, we find consistent evidence that high value-added teachers have a different profile of instructional practices than do low value-added teachers.  Teachers in the fourth (top) quartile according to value-added scores score higher than second-quartile teachers on all 16 elements of instruction that we measured, and the differences are statistically significant for a subset of practices including explicit strategy instruction.  Research Paper

Teacher Preparation and Student Achievement. Educational Evaluation and Policy Analysis, vol. 31, no. 4, pages 416-440, December 2009.  Donald Boyd, Pamela Grossman, Hamilton Lankford, Susanna Loeb, and James Wyckoff.

There are fierce debates over the best way to prepare teachers to improve outcomes for the students they teach.  Some argue that easing entry into teaching is necessary to attract strong candidates.  Others argue that investing in high quality teacher preparation will better serve our nation's children.  Even among those who believe that high quality preparation is important, there are sharp contrasts concerning the best approach.  Most agree, however, that we lack a strong research basis for understanding how to prepare teachers to meet the challenges of urban schools.  This study is a first step towards developing evidence to inform these debates, looking carefully at the ways in which teachers are prepared and the consequences of that preparation for pupil learning.  The research employs detailed data on New York City teachers, their preparation and the student achievement outcomes of their students.  Journal Article

Measuring Effect Sizes:  The Effect of Measurement Error.  June 2008.  Donald Boyd, Pamela Grossman, Hamilton Lankford, Susanna Loeb, and James Wyckoff. 

In this paper we focus on two issues pertaining to how effect sizes are measured.  We argue that model coefficients should be compared to the standard deviation of gain scores, not the standard deviation of scores, in calculating most effect sizes.  Second, we develop a measure that accounts for test measurement error.  Since the standard deviation of observed scores in the denominator of the effect-size measure reflects measurement error as well as the dispersion in the true academic achievement of students, it overstates variability in achievement.  We apply these adjustements to student assessments in New York City and find that effect-size estimates based on the dispersion in gain scores net of test measurement error are four times larger than effect sizes typically measured.  We explore the implications for such an adjustment to the estimated effect sizes of teacher qualifications on student achievement.  Research Paper

The Narrowing Gap in New York City Teacher Qualifications and Its Implications for Student Achievement in High-Poverty Schools. Journal of Policy Analysis and Management, vol. 25, no. 4, pages 793-818, 2008.  Donald Boyd, Hamilton Lankford, Susanna Loeb, Jonah Rockoff, and James Wyckoff. 

No Child Left Behind, state assessment-based accountability policies and new routes into teaching have all had profound effects on the labor market for teachers.  In this research we explore how the distribution of teacher qualifications and student achievement in New York City have changed from 2000 through 2005 using data on teachers and students.  The paper examines the role that readily observed measures of teacher qualifications have on student achievement.  Journal Article, Research Paper, Policy Brief.

Who Leaves? Teacher Attrition and Student Achievement. September 2007. Donald Boyd, Pamela Grossman, Hamilton Lankford, Susanna Loeb, and James Wyckoff.