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A memorandum stating that new math acceleration procedures will be implemented this spring was provided to District 65 School Board members as part of the packet of materials they were given for their April 28 Board meeting. The memorandum was prepared by Suzanne Farrand, math curriculum coordinator, and Lora Taira, chief information officer.

The memorandum says the District will consider fifth-graders for acceleration to Math 7 if they have a “Propensity Score” of 117 or higher; and they will consider sixth-graders for acceleration to Algebra 1 if they have a Propensity Score of 108 or higher.

The ECRA Group, consultants to District 65, is calculating a “Propensity Score” for every student as part of the teacher appraisal system. A Propensity Score of 117 is at approximately the 85th percentile locally, meaning at or above 85% of District 65 students in the same class. A Propensity Score of 108 is at approximately the 60th percentile locally, or at or above 60% of District 65 students in the same class.

The memo states, though, that parents may request that their child be considered for acceleration, even if the Propensity Score for math does not support the recommendation.

If a student is in the pool of students to be considered for acceleration, teachers and principals will use certain test information, a teacher inventory, a student inventory and parent feedback to determine whether the student will be accelerated.

The RoundTable has been advised that all seventh-graders who have not taken algebra will be considered for placement in Algebra 1 or Algebra 8. The memorandum lists information that will be considered to make this determination.

Board President Tracy Quattrocki said the new procedures are a “work in process,” and the District “will be testing and verifying” to make sure that the procedures are doing what they are intended to do, “which is keep the numbers flexible and provide for testing for as many kids as we think should be tested, without relying on rigid cut-off scores.”

Barb Hiller, chief administrative officer, said, “We welcome input from parents who would like to share their concerns.”

Propensity Scores

ECRA uses a student’s scores on multiple prior tests to calculate a Propensity Score. The Propensity Score captures “expected future performance given past performance,” John Gatta, Ph.D., president and chief operating officer of ECRA, told the RoundTable.

Dr. Gatta says ECRA enters a student’s past scores on multiple and different tests (e.g., one ISAT test and several MAP tests) into its algorithm. He says, the algorithm correlates the scores on the different tests (e.g., ISAT and MAP scores); it gives different weights to different tests in an effort to maximize predictive precision; and it applies a regression equation that calculates a Propensity Score for each student.

“The Propensity Score is scaled to represent the student’s achievement relative to the mean (100) and standard deviation (16) of prior students in the same grade and district,” says ECRA.

Using this scaling system, the mean (i.e., the average) Propensity Score is 100. Students who are one standard deviation above the mean have a score of 116, those who are two standard deviations above the mean have a score of 132, etc. Those who are one standard deviation below the mean have a score of 84, those who are two standard deviations below the mean have a score of 68, etc.

ECRA says, 68% of students typically have a propensity score between 84 and 116 (which is plus or minus one standard deviation) and 95% of students typically have a score between 68 and 132 (which is plus or minus two standard deviations), etc. This is a typical bell curve.

Each Propensity Score equates to a percentile rank. For example, the following Propensity Scores have the percentile ranks indicated: 68 (2.28 %ile); 84 (15.86%ile); 100 (50%ile); 116 (84.13 %ile); and 132 (97.72 %ile).

The scale is calibrated using District 65 data, Dr. Gatta told the RoundTable. So, for example, a Propensity Score of 100 for a District 65 third-grader calibrates to the average propensity of a third-grader in District 65, as opposed to a third-grader in the state, or in the nation.

Moreover, when ECRA says 68% of the students typically have a Propensity Score between 84 and 116, that means 68% of District 65 students will typically have a Propensity Score in that range. “When we talk about what is typical, it’s typical at District 65,” said Dr. Gatta.