This is the first post in a series that looks at data from charter schools’ Basic Education Data System (BEDS) reports. This data was provided to us by the New York State Education Department via a Freedom of Information Law request. A full spreadsheet with the data we used is available here.

One of the largest issues in the charter school debates has been accusations that charters “counsel out” students who have learning disabilities or who do not adhere to the schools’ strict codes of conduct. While we haven’t found comprehensive statistics that track individual students enrolled in charter schools from year to year, the BEDS reports include a “student stability” number that is relevant to this issue.

Student stability counts the number of students who are currently enrolled in the highest grade that the charter serves who were also enrolled in the school last year. For instance, if a charter school serves students in kindergarten through eighth grade, the student stability number would look at the number of current eighth-graders who were also seventh-graders last year.

We found that, on average, charter schools retain 84% of their students, compared to 93 percent for traditional public schools citywide. (The stability rate for traditional public schools varies from district to district, with a 91 percent stability rate in District 5, for instance.) This percentage has remained constant for the past three years but the percentage at individual schools varies widely. Some schools, such as the Beginning with Children Charter School and the Harbor Sciences and Arts Charter School, experience almost no attrition. Others, such as Harlem Day Charter School and the John V. Lindsay Wildcat Academy, consistently lose more than one third of their class. And for many charter schools whose highest grade was ninth, the attrition was noticeably high, probably because many of their eighth-graders chose to go to other, perhaps more well-known, high schools.

To better visualize the data, we have created a map that shows all of the charter schools that had applicable data. The size of the dot corresponds to the percentage of students that left the school, and if you hold your mouse over the dot you will be able to see relevant information such as grade studied, number who stayed in the school, and number who left. You can zoom in on certain districts, choose to look at the stability ratio for specific grades, or click to see the stability number of specific schools by using the menu to the right. Unfortunately, this data is only for the 2008-2009 school year — to see the numbers for 2007-2008, you will have to look at the spreadsheet. (Note: If you’re looking at this blog in Safari, you need to enable third-party cookies in order to see the graph.)

 

 
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It is important to note that these stability numbers only look at one grade in a particular charter school. Furthermore, the BEDS data, while vetted by the State Education Department, is not without its flaws. These include the timing of the report (charter schools must report their numbers in mid-October) as well as the lack of substantial follow-up by the groups that collect the data.

Nevertheless, we believe that this information provides important insight into charter school stability. As always, we welcome your feedback for ways we can improve and build on this report.

UPDATE: Many readers have pointed out that comparing charters’ stability numbers to stability numbers citywide may be slightly misleading. Others have mentioned that I neglected to take into account the number of students that charters retained in grade, as well as the fact that including stability numbers from schools whose grades went from 8th to 9th might slightly distort the numbers. I’ve updated the spreadsheet to include these concerns, but the numbers remain relatively the same. For those of you interested in district comparisons in the three main areas where charters are most numerous, the numbers are:

South Bronx (Districts 7, 8, 9): Charter Stability: 88 percent, District School Stability: 91 percent
Harlem (Districts 3, 4, 5): Charter Stability: 85 percent, District School Stability: 93 percent
Central Brooklyn (Districts 13, 14, 16, 17, 18, 19, 23, 32): Charter Stability: 87 percent, District School Stability: 92 percent