Measuring Principals' Effectiveness: Results from New Jersey's First Year of Statewide Principal Evaluation

Publisher: Washington, DC: U.S. Department of Education, Institute of Education Sciences, National Center for Education Evaluation and Regional Assistance, Regional Educational Laboratory Mid-Atlantic
Aug 30, 2016
Mariesa Herrmann and Christine Ross

Key Findings:

  • Nearly all principals received effective or highly effective overall ratings. Variation in the overall ratings was limited, with 99 percent of principals rated as effective or highly effective.
  • The percentage of principals who received highly effective overall ratings was lower for principals who were evaluated on school median student growth percentiles than for principals who were not evaluated on this measure. When school median student growth percentiles were not available, principal goals factored more heavily into the overall rating, and most principals received higher ratings on principal goals than on school median student growth percentiles.
  • Principal practice instrument ratings and school median student growth percentiles had moderate to high year-to-year stability. But school median student growth percentiles changed more across years in smaller schools than in larger ones.
  • Several component measure ratings—school median student growth percentile ratings, teachers’ student growth objective ratings, and principal practice instrument ratings—as well as the overall rating, had low, negative correlations with student socioeconomic disadvantage. This suggests that these ratings are biased against principals of schools with more disadvantaged students or that less effective principals are serving schools with more disadvantaged students.
  • Principals’ ratings on component measures had low to moderate positive correlations with each other. This suggests that the components measure distinct dimensions of overall principal performance.
New Jersey has implemented a new principal evaluation system to improve principal effectiveness, beginning with a pilot in 2012/13 in 14 school districts and statewide implementation n 2013/14. In 2013/14 half of a principal’s overall rating was composed of two measures of practice—a principal practice instrument selected or developed by each school district and an evaluation leadership instrument developed by the New Jersey Department of Education—and half was composed of measures of student achievement. This study examined data from 2013/14, the first year of statewide implementation. It examined four statistical properties of the system’s component measures: the variation in overall and component measure ratings across principals, the year-to-year stability of overall and component measure ratings, the correlations between component measure ratings and characteristics of students in the schools, and the correlations among component measure ratings. Information about these properties of the measures can inform efforts to improve the principal evaluation system and revise the guidance districts receive.