How to use raw scores and percentile rank to interpret student performance
Both the raw score and percentile rank are important when interpreting students’ performance.
While student growth can be observed by increases in raw scores over time, and this would demonstrate improvement, other students are also growing their knowledge and skills.
Raw scores usually go up over time. But much of this growth is usually due to students learning with their teachers. Thus, if raw scores are going up (improving) for a given student, but their performances relative to their peers (i.e., their percentile ranks) remain low or nearly flat then they are falling further and further behind their grade-level peers who are continuing to grow.
In other words, raw scores can often go up giving the appearance of meaningful growth, when we “know” that the growth is not enough because it is quite low relative to their grade-level peers. Raw scores don’t really tell you that much unless you also look at the percentile ranks. Some growth over the course of the year is expected, but you need to check the percentile ranks to see if the growth that students made was actually steeper than the growth made by same-grade peers over that time period.
This is the reason that both raw scores and percentile ranks must be considered to interpret student performance.
Additional Information: In general, the goal is to have students performing at the 50th percentile (or gray line on graph) in their given grade at a given time of the year (Fall, Winter, Spring benchmarks). Students who score at or above the 50th percentile do not need further testing until the next benchmark testing period. Those that score below the 50th percentile are indicating further testing, along with guided instruction from the teacher, in order to improve their raw/percentile scores.
Raw scores show an individual students' growth over time. For students performing below their peers both raw and percentile scores, their rate of growth needs to be higher in order to catch up to the average, or 50th percentile (which is the goal).
For significant student growth, a more intensive progress monitoring approach is necessary:
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