Charter School Student Attrition: The Case Of Harmony Middle Schools

Posted on April 9, 2011


This short post is a teaser about a charter school study I am currently working on that examines student disappearance rates, ability levels of students entering charter schools, and the ability level of students leaving charter schools. This teaser post focuses on Harmony Schools in Texas run by the Cosmos Foundation. Recent attention has been focused on the schools’ ties with the Gulen movement in Turkey and the use of H1B visas to replace American teachers with Turkish teachers. While I am interested in those issues, I focus on student mobility patterns and student achievement related to those patterns.

This study was  funded by the Texas Business and Education Coalition ( , an independent organization focused on improving school outcomes for all students.

I chose to focus on Harmony Schools because supporters of these schools have claimed on a number of different websites that my figures are wrong and I have falsely claimed high disappearance rates for Harmony schools. This post will surely lay rest to this issue. At least for Harmony Schools in Texas.

Data for the Study

The study relies on individual student-level data purchased from the Texas Education Agency. The data has the Texas Assessment of Academic Skills (TAKS) scores and the school/school district in which the student was enrolled during the spring administration of the TAKS tests. Thus, the data can be used to follow students from one year to the next as long as they are enrolled in a grade level in which a TAKS test is administered. In Texas, this includes grades 3 through 11. Students not taking the test, but enrolled in the school are still included in the data. The data is masked for FERPA compliance, but student masking simply removes the test score, not the enrollment data.

For a school to be eligible for the study, it had to have at least 10 students enrolled n grade 6 in 2008, grade 7 in 2009, and grade 8 in 2010.

Measuring Student Disappearance

Student disappearance was defined as the percentage of students enrolled in the 6th grade in 2008 who were still enrolled in the school in any grade level in 2010. Students could still be enrolled in another public school school in Texas or could have left the Texas public school system to move to another state/country, enter a private school, or participate in home schooling.

Figure 1 has the percentiles for all schools, including charter schools and traditional public schools.  So, schools in the 90th percentile are those schools whose student disappearance rate is greater than 90% of all schools in the state. The average disappearance rate for the schools in the 90th percentile is 43.3%.The schools in the 10th percentile have student disappearance rates in the bottom 10% of all schools in the state. The average disappearance rate in such schools is 13.6%.

The data for public schools has not been corrected for schools in fast-growth districts where substantial percentages of students change schools when a new school opens. Ultimately, this correction will be included which will lower the disappearance rates for traditional public schools. Charter school disappearance has been corrected for transfer to a school under the same charter operator. For example, if a student transfers from one Harmony school in Houston to another Harmony school in Houston, then that student is NOT counted as having disappeared from the original school.

Student Disappearance Rates for Harmony Schools in Texas

As shown in Table 2, a number of Harmony Schools had disappearance rates that were extremely high relative to all schools. Indeed, 7 of the 13 schools had disappearance rates that were greater than 80% of other schools in the state (use the color-coding from Table 1  to see what percentile each Harmony school fall into relative to all other schools in the state. Red indicates a high disappearance rate and green indicates a low disappearance rate). Most of those who have disappeared from the schools have transferred into other schools. The percentage of students no longer enrolled in Texas public schools is provided in the last column.

What I find interesting is the claim that there are long waiting lists to enroll in Harmony Charter Schools. I don;t doubt the claim–I think there probably is a waiting list for such schools. But why do so many students choose to leave the Harmony Charter Schools after they have enrolled? Were they pushed out? Did they leave on their own? If they left on their own, what was the reason?

I believe the data suggests that a substantial number of students and parents become disenchanted with the schools and transfer to another school. I see no other explanation when over 50% of students leave a school. But I could be wrong.

Who Leaves Harmony Schools: Improving Achievement Through Dissappearance

Ah shown in Table 3, there were 614 students with valid math TAKS scores. Of these students, 46.9% scored more than .2 standard deviations below the school average (red rows) while 38.1% scored at least .2 standard deviations above the school average (green rows). Column 3 (% students disappearing from school) shows that lower performing students had a greater disappearance rate than higher performing students.Indeed, 61% of the lowest performing students (those who scored more than 1 standard deviation below the school average) disappeared from Harmony Charter Schools while about 31% of the highest performing students disappeared. Almost 55% of those who disappeared were low performing students (red rows) while almost 30% of high performing students (green rows) disappeared.

Thus, a disproportionate percentage of lower performing students disappeared from the school. This is one way to increase the overall average performance and obtain higher accountability ratings than otherwise would have been obtained.

Does this happen in other charter school systems? Yes. In traditional public school districts? Yes. So, we have to remember that these results may be typical of all charter and public district systems. The final report will place these numbers in the context of other charter and district systems.

I’m sure many of you are wondering if the same analysis can be done with KIPP schools. Yes, it can! I have already done that analysis and it will be released concomitant with the release of the report through TBEC.

More to come on charter schools,

But the next post will return to employment issues and the percentage of educators having a direct impact on student outcomes. I will tell you this–the number is high enough that budget cuts will force districts to cut teachers despite what Governor Perry and other Republican leaders are claiming.

Posted in: Charter Schools