The Teacher Data Reports on SchoolBook: An Explanation

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SchoolBook has published the teacher data reports using a new tool that was created by interactive journalists at The New York Times and WNYC. The goal of the tool: to make the data easier to understand and put the rankings into context.

Teacher Data Reports

Search for your school to view the recently released teacher data reports.

The tool can be found on Web pages created for every school whose teachers’ rankings were released on Friday by the city’s Department of Education. You can find those pages by typing in a school name in the box on the left.

You will find a wealth of data on that page, starting with an overall snapshot of the school, as told by the percentage of teachers at that school whose rankings in English or math were “above average” or high -- two of the city’s five ranking categories. You’ll also be able to see how that compares to schools across the city.

Below those school numbers are the names of individual teachers, grouped by grade. The numbers listed with the teachers’ names are the rankings, meaning that teacher’s place when compared to other teachers like her or him, on a scale of 0 to 99.

A teacher can have up to four rankings for each grade taught: for math during the 2009-10 school year, math career, English in 2009-10 and English career. Career rankings are based on one to five years of data.

The numbers are situated along a black line. That line indicates the margin of error for that teacher’s ranking. A fuller explanation, and an example, can be found on each school’s page.

Clicking on a teacher’s name brings up additional information: the number of children in the class the ranking is based on; an “expected” score based on the past performance and demographics of his or her students; and the actual average test score of those students. Test scores are reported as standard deviations above/below the citywide mean.

The difference between the expected score and the actual score is considered the “value added” by the teacher.

One more piece of information can be included with a teacher’s listing: his or her response or explanation of the ranking, as submitted to SchoolBook. We encourage teachers to add their responses.

A module that allows you to search by teacher name is also on that page.

For more information, see our FAQ.

In creating this tool, SchoolBook decided to showcase only the most recent and career rankings, since we agree with many critics that the older data is less useful. We wanted to make clear the margin of error, since one of the weaknesses of these ratings is the large margins. And we wanted to put every figure in the context of the school and expected scores.

All of the data were provided by the city’s Department of Education (ratings for teachers in charter schools and District 75 are expected to be released on Tuesday). A team of journalists spent several hours verifying the data, dealing with anomalies, searching for missing data and making sure everything worked as planned before posting it on our site.

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