Interpreting State Test Score Data

As teachers across the county receive the end of year test scores for their students, teachers need to be aware of the various scores they receive and hoe to interpret the scores. 

The score report received by North Carolina teachers will include a developmental scaled score. This is a three digit number such as 554. The first digit indicates the test edition. So this is the 5th edition of the test. The other two digits are the score the student received on the test. At times for some subjects for some years, this was a t-score with an mean of 50 and a standard deviation of 10 points. This is not the case anymore. Therefore, these scores have no real meaning, other than they can be compared within the same test in the same subject. For example a 550 in math is not the same as a 550 in reading. Also, because these scores are onto on a continuous scale they cannot be compared from year to year. For example a 550 in grade 4 is not comparable to a 550 in grade 5. 

So, with this information the teacher needs to look at other information that may be helpful in understanding a student's performance. Achievement Levels for proficiency is the basis for determining the status of a student and school for accountability purposes. In north Carolina, the proficiency rating goes from "non proficient" to level 3 Grade Level Proficient (GLP) to level 4 and 5. Students who score a level 4 or 5 are considered College and Career Ready Proficient (CCR). The percentage of students who achieve a CCR proficiency is used to report federal-level proficiency. It is important to not that these achievement level cut-offs are not determined by or connected to a given percentile rank score of the student. 

The next score a teacher may receive is a percentile rank score. If you are not certain what a percentile rank score is I suggest reading the information at this NWEA site.  An added feature of this page is the explanation that percentile ranks scores are not helpful in measuring growth. This is especially true when trying to aggregate growth of a group of students.

Percentile rank scores are NOT to be confused with percent correct.

Percentile ranks are determined by an analysis of the array of student scores for a given test on the year the test was developed. Generally, test that have a normal distribution of scores are easily used to computing percentile rank equivalent scores for each student raw score.  

Sometimes, As it happened in North Carolina this year, The state used the 2021 test score data and created a net percentile rank score for each corresponding scaled score. This makes comparing percentile ranks from last year's test reports impossible to do with any accuracy. 

Here is a chart of grade 4 and 5 scores from 2021 and 2022 to demonstrate the problem of comparing scores. 

																			5	554	4	84