Data and thoughts on public and private school funding in the U.S.
On Teacher Effect vs. Other Stuff in New Jersey’s Growth Percentiles
Posted on June 2, 2014
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In this post, I estimate a series of models to evaluate variation in New Jersey’s school median growth percentile measures. These measures of student growth are intended by the New Jersey Department of Education to serve as measures of both school and teacher effectiveness. That is, the effect that teachers and schools have on marginal changes in their median student’s test scores in language arts and math from one year to the next, all else equal. But all else isn’t equal and that matters a lot!
Variations in student test score growth estimates, generated either by value-added models or growth percentile methods, contain three distinct parts:
- “Teacher” effect: Variations in changes in numbers of items answered correctly that may be fairly attributed to specific teaching approaches/ strategies/ pedagogy adopted or implemented by the child’s teacher over the course of the school year;
- “Other stuff” effect: Variations in changes in numbers of items answered correctly that may have been influenced by some non-random factor other than the teacher, including classroom peers, after school activities, health factors, available resources (class size, texts, technology, tutoring support), room temperature on testing days, other distractions, etc;
- Random noise: Variations in changes in numbers of items answered correctly that are largely random, based on poorly constructed/asked items, child error in responding to On Teacher Effect vs. Other Stuff in New Jersey’s Growth Percentiles | School Finance 101:
