Hinsdale High School Teachers Association

Key to understanding what “class size” means is understanding how class size is measured, as the terms used to describe class size are often misleading or misunderstood. For example, what is an “average” class size? Often in response to class sizes concerns the District’s Pupil/Certified Staff ratio is cited as being below state averages. To the layman, this answer may suffice and even impress. But as educators, it is our duty to educate not only the students in our classrooms these figures attempt to quantify, but also ourselves on what these terms mean - especially in light of growing concerns by HHSTA educators over the size of their classes.

For example, Pupil-Certified Staff Ratio is defined by the Illinois State School Board (ISBE) on our Illinois State School Report Cards as:

Pupil-certified staff ratio is the fall enrollment divided by the number of full-time equivalent certified staff, excluding adult education personnel.

This ratio lumps all certified staff including special education teachers, social workers, guidance councilors, and administrators - professional educators who are not classroom teachers - into the ratio. Although these educators play important roles, when trying to determine what an “average” class size is, the inclusion of these non-classroom educators skew the average considerably lower than it really is.

Central’s Pupil/Certified Staff ratio for 2006-2007 was 12.5 to 1 (or twelve and a half certified staff members for each student), which is below the state average of 13.9 to 1. Although below the state average, this number ties the highest reported ratio for Central since the inception of the current ISBE School Report Card system in 2002.

Another measure cited on the ISBE Report card is Pupil-Teacher Ratio, which ISBE defines as:

Pupil-teacher ratio is the fall enrollment for the school year divided by the number of full- time equivalent classroom teachers in the district. Excluded are teachers classified as special education teachers.

Although a more accurate descriptor of class size due to the exclusion of special education teachers, Pupil-Teacher ratios still distort the overall average by not considering the number of classes (known as “sections”) each teacher is responsible for into the ratio. Many classroom teachers often have non-classroom related duties such as Department Chair positions or release period assignments that remove teachers from the classroom. Failure to account for these non-classroom assignments distorts this ratio lower than it is in reality.

Central’s Pupil-Teacher ratio on ISBE’s 2007 report card was 17.5 to 1, with a state average of 18.8 to 1. Although still favorable to state averages, this number represents the highest pupil-teacher ratio for Central reported on the current ISBE School Report Card system.

Average Class Size as reported on ISBE School Report Cards attempts to get to a truer picture of what an “average” class looks like by averaging enrollment with class sections attempting to achieve the most accurate number - the actual number of students in a typical classroom:

Average class size is the sum of specified class enrollments […] in all subject areas in high school, divided by the number of classes. For high schools […] an average for the 2nd and 5th class periods is used.

According to ISBE, Central’s average class size in 2006-2007 was 22.0 students, more than the state average of 18.9 students or the district average of 20.5 students. More concerning to educators however was that this is the largest average class size reported since the inception of the current ISBE School Report Card system in 2002.

Even though a better descriptor of class size, a two-period average of 2nd and 5th periods is still used in this model. ISBE also does not break the data out in relation to section size or type of course (i.e. Regular, Honors, AP, etc.). The HHSTA class size study at Central looked at all departments and the over 700 sections offered to Central Students that its members teach. The results showed:

Average All Class Size: 23.1
Average Core Class Size (English, Math, Science, and Social Studies): 22.4
Average Advanced Placement (AP) Class Size: 22.4
Percent of Classes with 13 or fewer students: 6.4%
Percent of Classes with 30 or more students: 9.6%

Now to end on a data related caveat: Data changes over time. Enrollments rise and fall year to year. Ratios change from year to year. The data examined from ISBE report cards is the 2006-2007 school year, with HHSTA’s study at Central was done in 2008. The question is whether these apparent increases are a trend or just a fluctuation in the data. Watching these ratios and averages in the future with an understanding of their true meanings should provide an answer.