IAR + ISA + HS Assessment, SY 2024-25
All grades, all students. % Proficient (Levels 4-5).English Language Arts
79.1%
State avg 51.0%
District avg 74.8%
County avg 66.1%
+14.7pp since 2023-24
Mathematics
70.9%
State avg 37.9%
District avg 67.2%
County avg 57.2%
+7.4pp since 2023-24
Science
60.0%
State avg 40.3%
District avg 64.7%
County avg 56.3%
-21.8pp since 2023-24
What this means: On the IAR + ISA + HS Assessment, Illinois's statewide test, about 79 of every 100 students at this school read and write at grade level, about 71 of 100 do math at grade level, and about 60 of 100 are at grade level in science. Across all Illinois schools, those numbers are about 51, 38, and 40. Reading and writing scores are up about 15 points since 2023, while math scores are up about 7 points and science scores are down about 22 points.
What is IAR + ISA + HS Assessment?
Illinois public-school students in grades 3 through 8 take the Illinois Assessment of Readiness (IAR) in English Language Arts and Math each spring. The Illinois Science Assessment (ISA) is administered at grades 5, 8, and 11. High school students take the SAT (or PreACT in current administrations) as the state accountability assessment.
What does "% Proficient (Levels 4-5)" mean?
It is the percentage of students at the school who scored at Level 4 ("Met Expectations") or Level 5 ("Exceeded Expectations") on the IAR 5-level scale. Levels 4 and 5 signal the student is performing at grade level or above. A higher number is better.
What does 79.1% mean for English Language Arts at Lester Elem School?
It means about 79.1 percent of students tested at Lester Elem School performed at grade level or above on the IAR + ISA + HS Assessment English Language Arts test in 2024-25. The statewide average for Illinois that year was 51.0%. The other students fell into the lower performance levels.
How is the state average calculated?
It is a weighted average, not a simple average of each school's number. We multiply each public school's score by how many of its students tested, add those together for all schools in Illinois, and divide by the total students tested that year. This way a big school with 1,500 students counts more than a small school with 50 students, which is the right way to ask "how did the typical student do this year?". District and county averages on this page use the same method, just scoped to that district or county.
Where does this data come from?
Illinois State Board of Education (ISBE), Report Card Public Data Set. Illinois Assessment of Readiness (IAR) for grades 3-8 ELA + Math, Illinois Science Assessment (ISA) at grades 5, 8, 11, plus the SAT / PreACT high-school assessment. Headline metric is the cumulative "Proficient" rate (Levels 4 + 5 on the IAR 5-level scale).
How often is it updated?
IAR + ISA + HS Assessment is administered once a year (spring). Results are released by the state in the summer or early fall. We refresh this page after each annual release.
