About 71 percent of Indiana's public school students passed both the English and math portion of the ISTEP+ in 2012, up from 70 percent last year. The scores mark an 8 percent gain since the 2008-09 school year.
In contrast, The Journal Gazette looked at 189 private schools with voucher students that administered the test and had 2011 data for comparison.
The passing rate for both math and English at those schools last year was 86 percent; in 2012 it dropped 1 percentage point to 85 percent.
"Some of the schools did see slight drops in their scores and we fully expected that," said Lindsey Brown, executive director of School Choice Indiana. "When a school takes on a large number of new students that's certainly going to impact its scores."
Brown said other choice programs nationwide have shown an initial negative impact before growing again.
The Indiana Department of Education has not yet run an aggregate calculation showing how many voucher students passed the test.
Lawmakers approved the nation's most expansive voucher program for low-to-moderate income families in 2011. It allows parents to send their children to private schools using state funding. Almost 4,000 students took advantage of the program for the 2011-12 school year.
Brown said that voucher schools overall performed better than public schools. Specifically she said 38 percent of voucher schools, or 86 schools, reached the 90 percent pass rate in both subjects, which the Indiana Department of Education set as a goal for every school.
Some drops at individual schools were quite large.
For instance, the Ambassador Christian Academy in Gary accepted 110 voucher students at the beginning of the school year. In 2011, 78 percent of the academy's students passed both the math and English portions of the test. That rate dropped to 57 percent this year.
Likewise, Columbus Christian School dropped from 89 percent passage rate to 71 percent after accepting 29 voucher students.
Repeated calls left at both schools were not returned.
Locally, a number of private schools with voucher students saw much smaller drops.
Blackhawk Christian Jr.-Sr. High had 91 percent of its students pass both math and English last year and 83 percent this year.
Bill Hartman, lead administrator at Blackhawk, said he wasn't shocked at all to see an overall statewide reduction for voucher schools.
"I think there is no question as you broaden the student population your test scores are not going to be as high," he said. "The more you pull the public into the private we will see that."
But he said he didn't think the drop at his high school this year was closely related because the majority of Blackhawk's voucher students were in elementary grades.
In fact, the elementary school's ISTEP scores went up slightly.
Likewise, Tommy Franke, principal at Ascension Lutheran School in Fort Wayne, said her school only had one voucher student this year, and he was at the top of his class.
Because of that, vouchers could not explain the drop from 89 percent to 85 percent of Ascension students passing both portions of the test.
Tina Voors, principal at St. Aloysius Catholic School in Yoder, said she hasn't analyzed closely yet the cause for her schools' drop of 10 percentage points.
"I prefer to look at how close they were to passing and whether they improved," she said.
"I'm looking forward to a day when there is not as much clout tied to ISTEP. We should look at how a student is doing in-house and how they are growing. ISTEP is just one factor."
- To check out ISTEP+ results from 2009 through 2012, check out jgdate.net.