Differences between standardized test scores at Oak Park's middle schools can be explained in part by the minority student achievement gap and by the rate of student transfers in and out of the schools, a District 97 administrator said.
A WEDNESDAY JOURNAL analysis of recently released Illinois Standards Achievement Test (ISAT) results shows that last spring's Julian Middle School eighth grade students show improvements in 7 of 10 categories over each of the past three years, whereas eighth graders at Brooks Middle School show none.
Categories include students as a whole and divided into four subgroups?#34;white, black, low income and students receiving special education?#34;for both the reading and math portions of the ISAT. Subgroups are defined by state and federal No Child Left Behind laws.
Brooks students made improvements in some categories in some years, but in no category was there improvement over the three-year period as shown at Julian.
School administrators are looking into just why students at Brooks differed from those at Julian, but there's no easy answer.
"Finding the cause, when so many factors are involved, can be difficult," said Mark Pickus, Dist. 97 student achievement data coordinator, in an e-mail message.
"Of course we would want to consider whether there are differences in the quality of the instructional programs. But another factor we are looking into is mobility."
Mobility refers to how frequently students transfer in or out of a school during a school year.
More than eight times the transfers
During the 2003-04 school year, 189 students transferred in or out of Brooks, while at Julian the number was just 23. That's more than eight times as many transfers at Brooks than at Julian.
As the district examines how mobility might affect its schools and ISAT performance, it will look at where those transferring in are coming from, and how long those transferring out have been in the district. Achievement profiles for both groups will be examined.
Pickus did not have an ethnic/racial breakdown of transferring students, but said he could provide one "if and when this info is about to be made public at a board meeting."
Factors other than mobility will be examined, too, Pickus said.
Testing differences, however, between elementary feeder schools does not explain differences at the middle schools, Pickus said.
Averaging scores in reading and math for students at Beye, Irving, Longfellow and Mann elementary schools?#34;the Julian feeders?#34;shows that 83 percent of students met or exceeded state standards on the ISAT. That average for Brooks feeders?#34;Hatch, Holmes, Lincoln and Whittier?#34;is 79 percent.
Elementary school students take the ISAT in third and fifth grade.
But that comparison is misleading, Pickus said. Mann Elementary did not have enough African-American third grade students for the state to consider them a viable subgroup statistically when the tests were taken.
"It is entirely reasonable to exclude Mann from the Julian feeders since white students are so over-represented that it makes the school a statistical 'outlier,'" Pickus said. "When that is done, the feeder school gap disappears completely."
In fact, the Brooks feeders score slightly higher than Julian feeders with Mann out of the equation.
"Even when comparing Brooks and Julian, the black-white achievement gap probably explains most of the achievement difference" for 2003-04, Pickus said.
Black students tested at a higher rate of meets-or-exceeds at Julian (53 percent) than at Brooks (49 percent), as did white students (Julian 94 percent, Brooks 90 percent), Pickus said. But those figures are narrower than averages for all students at both schools.
Thus, the greater proportion of black test-takers at Brooks than at Julian (42 percent compared with 34 percent) drives the differences between the schools, Pickus said.
"I think the data points to that issue as more significant than apparent differences between Brooks and Julian or their feeder schools," he said.