Apples and Oranges: Comparing Private and Public School Test Scores
Ever wished you could compare private and public schools somehow? Perhaps with test score data?
Private Schools: Different Tests for Different Purposes
Standardized tests have many functions. Some exist to provide an assessment of a student's knowledge, which teachers can then use to shape instruction. Others are designed to assess the student body as a whole in order to evaluate the performance of the school. Others are used for admissions.
Here are some common assessment tests used in private schools:
- ERB The Educational Records Bureau in New York City creates several tests used by more than 1,500 private schools and some public schools.
- ITBS The Iowa Tests of Basic Skills is used by private schools nationwide and some public schools, including those in Iowa. The test results are compared with national results and grade equivalents, helping teachers to judge students' progress and design instruction accordingly. The ITBS is usually given in the fall so that teachers can obtain the results early in the school year and use them to support student learning.
- TerraNova This is a series of tests used to assess students from kindergarten through 12th grade, in subjects ranging from reading to math to social studies and science. California uses this test as part of the California Achievement Test (CAT), which in turn is used by other states.
Henry Tyson, superintendent of St. Marcus Lutheran School in Milwaukee, chose the TerraNova for his school. "At the time MPS [Milwaukee Public Schools] was taking it, and we wanted to be able to compare ourselves to MPS. We stuck with TerraNova because we wanted five years of uniform data."
Common admissions tests used by private schools are:
Admissions tests are not given by the schools themselves - just as college admissions tests, the SAT and the ACT, are not given by colleges. To take the SSAT or the ISEE a student must register with the testing company. The school you are applying to will let you know which test to use. Then simply call or go online to register.
By Marian Wilde , GreatSchools Staff
Unfortunately, comparing private to public school test scores is a bit like comparing apples to oranges.
Public schools use their own stable of standardized tests, which they use for a variety of purposes: assessment and diagnostics, to name two. Private schools use a different set of tests - some derived from the same basic tests public schools use and created by the same companies - but still different enough that they can't be compared side by side with public school tests.
Public schools are required by law to administer the test chosen by the state government and to publish their test scores. Meanwhile, private schools are free to pick their own standardized tests and, because they don't rely on public funds, do not have to release their scores, though interested parents can ask to see them.
A parent in research mode cannot even compare public schools across state lines because of the wide variety of tests in use nationwide. In order to do that, all public schools would have to administer the same exam. Currently, only schools in a given state do that.
For better or worse, standardized testing seems to be here to stay. The question now is how to use test score data wisely. With that goal in mind, a handful of education researchers and school officials are working to achieve greater transparency and accountability for all types of schools.
One Way to Compare: NAEP
Several recent large-scale studies have compared private schools to charter and regular public schools using the one common test taken by selected samples of students around the country.
That test is the National Assessment of Educational Progress (NAEP), otherwise known as the Nation's Report Card. Administered by the U.S. Department of Education, the NAEP is given to students in grades 4, 8 and 12 in both private and public schools.
One of these studies, conducted by Christopher and Sarah Theule Lubienski, a husband-and-wife team at the University of Illinois, compared more than 340,000 students using math scores from the 2003 NAEP. The study found that after adjusting for socioeconomic factors, there is little difference between private and public school scores. According to the researchers, "Demographic differences between students in public and private schools more than account for the relatively high raw scores of private schools. Indeed, after controlling for these differences, the presumably advantageous 'private school effect' disappears, and even reverses in most cases."
Similarly, another study - Comparing Private Schools and Public Schools Using Hierarchical Linear Modeling - used the 2003 NEAP data. It found that after adjusting for student characteristics such as gender, race, ethnicity, disability status and English-language proficiency and for school characteristics such as size, location and the makeup of the student body, the fourth-grade reading test scores were virtually the same for private and public schools, although the math scores for public schools were higher. In eighth grade, private school students performed better in reading, but there was virtually no difference in math.
Why Most Private Schools Don't Publish Test Scores
Public schools are required by state and federal regulations to publish their test scores, but private schools - operating without public funds and outside of close government supervision - are not obligated to do so.
Just as in the public school arena, the private school community debates how much emphasis to place on test scores. Many private schools pride themselves on providing creative and nurturing environments rather than a one-size-fits-all education. Patrick F. Bassett, president of the National Association of Independent Schools, writes on the NAIS Web site that, "those who understand curriculum and instruction, and who are rightfully skeptical about the value of standardized tests in general, also worry very much about the deleterious impact of the movement on children. With all the memorization and test preparation, will students still be taught to think critically? Will they learn to love learning?"
Others argue that private schools should report how well they are doing to the community. Henry Tyson, superintendent of St. Marcus Lutheran School in Milwaukee, believes that publishing private school scores will help parents make informed decisions when choosing schools. "The reality is that there is very little accessible, useful information that parents can use," says Tyson. "The critical problem right now is that thousands of parents [in Milwaukee] are choosing very bad schools for lack of good information."