# Why do the differences in student growth projections vary for some subjects more than others?

Document created by Community User on Oct 30, 2017Last modified by Community User on Oct 30, 2017
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Why do the differences in student growth projections vary for some subjects more than others?

Depending on the subject and grade, the growth projections for students can either vary widely across students of all different achievement levels, or they can be fairly constant for all students. We often get asked the question as to why this is, and the short answer is that the actual growth for these students reflects these trends. This is explained further in the example below.

Growth projections are based on our nationally representative norms. If you look at the fall to spring (F to S) projections for 5th grade math, students across the achievement distribution – low achievers and high achievers alike – all have growth projections of approximately 10 points. By contrast, for 5th grade reading, students have much more variable growth projections, with students at the 10th percentile having growth projections of approximately 9 points, while students at the 90th percentile have growth projections of approximately 3 points.

In the figure below, you can see the actual average growth for all 5th graders who tested in math during the 2015-16 school year. This information is presented by starting percentile (achievement), ranging from the 5th to 95th percentile. As you can see, the average growth for the vast majority of 5th grade students in math is right around 10 points of growth. It’s worth pointing out that our norms are nationally representative but our partner base is not, so we wouldn’t expect the average growth for our partners to perfectly reflect that of our norms. However, given that our norms are based on our partners' data, we’d expect the trends to be pretty consistent, and that’s what we see in this particular figure. Also, our norms don’t explain why student growth patterns are what they are – they merely reflect what is occurring. So we can’t say why it is that students all tend to show about the same amount of growth.

5th Grade Math - Mean Raw Growth vs. Percentile, Fall 15 to Spring 16

Below are the reading results for those same 5th grade students. As you can see, the pattern of actual growth for these students is much different, with high achievers showing lower raw gains than low achieving students. And, this pattern is reflected in the growth norms, with the average student showing about 6 points of growth, but with much more variability across the achievement distribution in terms of student growth projections.

5th Grade Reading - Mean Raw Growth vs. Percentile, Fall 15 to Spring 16

So, the short answer for why you’re seeing different patterns in the growth projections is because those reflect the actual patterns of growth we see for students across the nation.