Tuesday, February 1, 2011

What's Wrong with the CREDO Report?

In the blog post below,http://animashighschool.blogspot.com/2011/02/across-us-charter-school-movement-grows.html the article uses an often cited study to represent a counter argument to the success of the Charter School movement. Specifically:

A 2009 study by Stanford University found that only 17 percent of charter schools performed significantly better than traditional public schools while 37 percent performed worse and 46 percent showed no big difference.


As I find myself speaking publically about AHS and the greater Charter School movement, it's important to understand how the CREDO report is used by critics to counter charter school success. Below, I've posted two very credible and accurate assessments of the Stanford study.

First, is a link to Nelson Smith's report CREDO Reconsidered. I had the good fortune of taking a class from Mr. Smith this past fall at Harvard and he went into great detail concerning the flaws in the CREDO team's research techniques. You can read his summary here:

http://www.publiccharters.org/files/publications/CREDO%20Reconsidered%20-%20final.pdf

Second, is a report from www.edreform.com which offers additional context and information about the shortcomings of the CREDO report.

I wanted to make sure that these resources are available for anyone trying to find credibilitiy in CREDO. Enjoy!
---------------------------------------------------------------


See this report at:http://www.edreform.com/_upload/No_More_Waiting_Charter_Schools.pdf


www.edreform.com October 2010

FACT-CHECKING CHARTER SCHOOL ACHIEVEMENT
Why some are saying only 1 in 5 charter schools perform, and why it’s wrong

Throughout the media in recent months, a statistic is often repeated that suggests charter school achievement is “mixed” and that only 1 in 5 charter schools actually perform well. This started in June 2009, when The New York Times published a report on a study by a small research center out at
Stanford University, whose press releases for each of the 15 states studied said that charter schools usually did no better or worse than traditional public schools.



It’s been repeated by everyone from Joe Scarborough to Education Secretary Arne Duncan. The problem is that it’s not even remotely true.
The source of this new conventional wisdom about charters is the Center for Research on Education Outcomes (CREDO). Their report is flawed in several ways:


• It was not a national study but a study of only15 states. Forty states plus DC have charter school laws.

• It deployed a method of comparing students in charters to “virtual twins” in traditional public schools. These children are composites of what the researchers believe the student in a traditional public school would look like, not what they DO look like.

• The study did not account for any variation in grade levels of schools. Some charters run from K-3, starting a new grade each year; others start at 3 and go to 8 and so on. The number of years a student was in a charter is completely ignored.

• The researchers ignored the gold standards of research that requires apples to apples comparisons. That means that the achievement of a student that is already in a charter but would have gone to the precise neighborhood school of the student to whom he is compared in the traditional public school.

• The researchers ignored variations in state test rigor, reporting and data, and made comparisons of students regardless of state boundaries.

• The study accounted for poverty using federal free and reduced lunch program data, which the federal research bureau that collects that data has admitted is deeply flawed, as most charters do not participate fully in the free and reduced lunch program for a variety of welldocumented reasons. That does not mean they do not feed students; it means they prefernot to comply with US Department of Agriculture paperwork and regulations that are
costly and often negate the funds they’d receive.


The Center for Education Reform – Charter Achievement October 2010

Following is evidence to support these high level points:

1. CREDO’s results rely on the invention of fake children in conventional public schools for the purposes of gauging the learning gains by students in charter schools. Instead of comparing real students who attend charter schools to real students who attend conventional public schools, CREDO has merged demographic data to create so-called “virtual twins.” This is a highly subjective and easily manipulated way to gauge the effectiveness of a school.

• The study’s authors have admitted that it is easier to “generalize” about a charter school by creating so-called virtual twins, while admitting that head-to-head studies (referred to as “Lottery Studies,”) are superior to their approach. According to respected researcher Caroline Hoxby of Stanford, Harvard, and the National Bureau of Economic Research, “the CREDO study does not have data on charter schools’ admissions lotteries, so it does not use a randomization-based method of evaluation. Randomization is the ‘gold standard’ method of evaluating charter schools’ effects on student achievement because it effectively
eliminates all forms of selection bias so long as (i) randomized admissions lotteries were used and (ii) a sufficient number of students participated in them.”


• There is no such thing as a virtual student or virtual student achievement. Reports that attempt to virtually replicate a demographic profile of a charter school student by ethnicity, age, socio-economic status and match these averages with one or more conventional public school students can be easily manipulated by selecting certain types of data and eliminating others. Hoxby explains that the CREDO study, “matches each charter school
student to a group of students in traditional public schools. A charter school student can potentially be matched to a group that contains many students… Thereafter, the study treats these group averages as though they were students,” themselves.


• To successfully use the “virtual twin” methodology, students currently in a charter school had to have been previously enrolled in a conventional public school long enough to have a profile, and their attendance would have to be linked to state test data. CREDO did not do this. Twins were not created with state test data. Instead, they were created by scores from the National Assessment of Educational Progress — which provides snapshots of
state performance and is not to be used to develop “virtual twins” or gauge individual school performance.


• Even if the process were completed accurately, it is statistically impossible to come even close to a “virtual twin” for 20 to 25 percent of charter school students.

2. CREDO’s report does not take into account the higher percentage of charter elementary and middle schools, leading to inaccurately weighted aggregate data. In addition, CREDO’s analysis only looks at three years of a student’s education. The study’s failure to look at students over a
longer period of time leads to unrealistic outcomes and a flawed picture of the impact of charter schools.


• CREDO’s assertion that charter elementary and middle school students are positively impacted compared to their peers in conventional public schools, but negatively impacted in high schools and “multi-level” schools, is misleading because high schools make up sucha small number of charters, thus skewing CREDO’s overall data.

• In reality, 56 percent of charters serve elementary and middle school grades, or K-8, while only 22 percent of charters are high schools, or serving grades 9-12. Most charter schools are not classified as they are “multi-level” schools.

• Research has shown that whenever a child switches schools, whether elementary to middle, or a traditional public to a charter, there tends to be a drop in the student’s academic achievement level. This recovers after two or three years.

• In reality, long-term studies demonstrate strong growth for students who stay in charter schools. For example, on average, a student in New York City who attended a charter school for all of grades kindergarten through eighth would close about 86 percent of the achievement gap in math and 66 percent of the achievement gap in English. In Washington, D.C., high school graduation rate for DC charter schools is 24 percentage points higher
than at conventional public high schools.


3. CREDO’s study has been discredited by the nation’s leading charter school achievement researcher, Caroline Hoxby, for not following the “gold standard” of charter school research.

• According to Hoxby, whose work was also published by Stanford University and the National Bureau of Economic Research:

A recent study…by CREDO…contains a statistical mistake that causes a biased estimate of how charter schools affect achievement. Essentially, the achievement of charter school students is measured with much more error than the achievement of the controls, which are not individual students but are group averages of students in the traditional public schools. [This] forces the
estimated effect of charter schools to be biased, and the bias is negative…the CREDO study also violates four rules for the empirically sound use of matching methods to evaluate other charter schools’ effects.


4. CREDO's analysis does not account for the great variances in charter laws from state to state or how those laws may differ from paper to practice.
• The report suggests a negative correlation between student achievement and multiple authorizers. In fact, such charter authorizers vary greatly in law and practice, as CER’s 2010 study and scorecard demonstrate. There is clear evidence that charters students succeed in states with a number of meaningful, independent and highly accountable authorizers who compete for chartering.

• The states reported to have significant learning gains are in fact, states which have earned an average "C" grade for the strength of their law, based on CER's 2009 charter law analysis.


5. CREDO claims that charter schools lead to lower performance among Black and Hispanic students but higher achievement gains for low-income students. This is flawed, because most of the low-income students served by public charter schools are minorities. CREDO’s failure to recognize this overlap leads to skewed results.

• CREDO relies solely on federal free and reduced lunch program data in its analysis of poverty vs. ethnicity. In reality, the National Center for Education Statistics’ former commissioner, Mark Schneider, has joined with leading experts to call lunch program data a “poor proxy for poverty.” Moreover, the 2010 Annual Survey of America’s Charter Schools found that 39 percent of charter schools do not even participate in the free and reduced lunch program because it is an onerous process.

• In reality, 50 percent of students in charter schools are deemed at-risk and 50 percent of children in charter schools are nonwhite. Further, 40 percent or more of charter schools serve student populations that are over 60 percent minority, at-risk or low income. Charters in urban areas, such as New York City, Detroit, or Washington, DC, serve student populations that are nearly 100 percent minority or at-risk.

CHARTER TRUTHS

Individuals seeking verifiable charter school research need to know that there are reports with much more credibility, and much more reliability, than the one produced by CREDO. For example, the following data points indicate the success and achievement of charter schools nationwide.

Student and School Achievement

• By the end of eighth grade, a charter student would be scoring 30 points higher in math than if he remained in a traditional public school, according to Hoxby.

• In Colorado, 85 percent of charter elementary schools made Adequate Yearly Progress (AYP), compared to 73 percent of conventional elementary schools. Eighty-one percent of charter middle schools also made AYP, compared to only 49 percent of conventional middle schools.

• In New Orleans, the number of fourth grade students who met or exceeded grade level in English rose from 44 percent in 2005 to 59 percent in 2009. Eight graders who met or exceeded grade level increased from 26 percent to 42 percent of students.

• Eighty-one percent of all charter schools in Georgia made AYP compared to 79 percent of traditional public schools.

• At SUNY-authorized schools in New York, charter students are performing better than their non-charter peers. Eighty percent of students in grades three through eight scored at or above proficiency in ELA in SUNY schools, compared with 77 percent of all public school students. In math, 92 percent of students scored at or above proficiency compared with 86 percent of all public school students.

• California's school Academic Performance Index (API) is calculated from student test scores on a scale of 1 to 1,000. Analyzing the growth of school's API scores from 2004 -2007, it shows that 17 percent of charter schools have had significant growth, over 50 points, compared to only 6 percent of traditional public schools. In Los Angeles, charter schools had a 2008 median API score of 728 as compared to a median API score of 663 for conventional public middle schools.

Charter School Accountability

• Since the beginning of the charter school movement, only 13 percent of charter schools (657 of the 5,250 schools ever created) have ever closed their doors.

• Of the charter schools that have closed, only 14 percent closed because of academic reasons. This means that charters have a significant rate of success despite being held to much higher standards than conventional public schools.

Charter School Demand

• 65 percent of charter schools have waiting lists, an increase of 6 percent over 2009.

• Parental demand for charter schools surged by 21 percent in 2010.

• In some areas of the country, such as North Carolina, no new charters may open unless one closes. It is estimated that the waiting list for all charter schools combined in Texas is currently over 40,000 students. Cities are also constricted by caps; Boston, Massachusetts has over 8,000 students on waiting lists because of the numerous restrictions on charter
growth.

The Center for Education Reform
910 Seventeenth Street, NW • Suite 1100 • Washington, DC 20006
800-521-2118 • 301-986-8088
www.edreform.com