Statewide Screening Window

Window Administration Dates

Fall August 1 – October 24, 2025
Mid-year
December 1 – January 30, 2026
Spring March 16 – May 8, 2026

Situation Concern Valid interpretation & Explanation
Student has the same score across two seasons and the national percentile is different.  "How did the student perform the same but also worse?"  National percentile rankings for a measure's scores are adjusted based on how scores increase across the school year as students learn. Norming data shows that scores increase from Fall to Winter to Spring. Therefore, national percentile rankings for a certain score are almost always lower for a testing season later in the year.
Student had a perfect score, but national percentile is <99th percentile.  "Why isn't the highest score the 99th  percentile?"  National percentile rankings for the maximum score on an assessment will indicate the percentage of peers that their score was higher than. A national percentile ranking less than the 99th percentile for a perfect score means that more than 1% of students in the norming sample achieved a perfect score.  This is not uncommon for short screening measures designed for detecting deficits in fundamental abilities, because these abilities are often very easy for high achieving students. 
 
For example, if 10 percent of students in a sample achieve perfect scores, we can confidently report that perfect scores tested better than 90% of the sample. But there is not enough information from the results to tell the difference between the top 10%, so we can't assume any one student has abilities that are actually better then 99% of peers.
The student had a perfect score in two seasons, and the national percentile went down.  "How can perfect performance get worse?"  The student has shown perfect mastery of the skills assessed by the measure at both times. The student's skills have likely exceeded what the measure can assess (this is known as a ceiling effect).  
 
Throughout the year the percent of students achieving perfect scores goes up, so the percent of students scoring with scores less than perfect goes down. This is what the lower national percentile ranking for perfect scores later in the year is saying.
The test is showing ceiling effect, and is not capturing differences in performance between the most advanced students. "Should we still trust screening results?"  When using assessments to screen for students at risk of learning deficits the priority is to observe differences in performance among low achieving students and minimizing testing time. For example, Act 20 reporting requirements care about detecting when students are performing below the 25th percentile. A short assessment that is very easy for high achieving students is still a valid and effective tool for to screening for students with deficits in fundamental abilities.