In the education system, the grading curve is a widely used method that helps to adjust students' scores. We will explain the Square Root Curve grading method which is commonly used in the grading system.
This method allows us to adjust the scores of the poorly performing students while ensuring that the higher scores increase at a slow rate. In this post, we will explore its formula, definition, and real-world example.
The Square Root Curve is a grading method that helps students balance difficulty and fairness. This concept is mainly used when an assignment or exam is tough; it ensures that students who performed poorly still receive a reasonable grade improvement. Dive deep to discover the formula and a real-world example.
We will need the following formula in order to precisely calculate the Square Root Curve:
Formula:
If you want to reverse the process to get the original percentage grade, you just need to use this formula
How to use Square Root Curve Calculator?
Using our calculator is fairly simple. There are only two inputs — you can fill in either one, and the other will automatically show the calculated value.
Let's assume you have put a value of 49 inside the Percentage Grade input; the Square Root Curve Grade input will instantly show a value of 70. That's simple, if you are still not sure, follow this set of instructions:
49.70.That’s how simple our square root curve calculator is — keep reading to learn more about the formula, real-world example, and much more.
Below, we have prepared a visual representation of the Square Root Curve chart:
Let's look at an example to understand the square root curve concept deeply.
Example:
Suppose a student's score is 49% in an exam; let's compute using the formula:
Thus, after using the Square Root Curve the student now gets a new grade which is 70%.
This concept is widely used in various grading systems; the following are some real-world applications.
We have built a table that showing calculated square root curve ranging from 0 to 100 values. Let's see in the table below:
| Raw Grade | Curved Grade | Formula Used |
|---|---|---|
| 40 | 63.25 | √40 × 10 |
| 50 | 70.71 | √50 × 10 |
| 60 | 77.46 | √60 × 10 |
| 70 | 83.66 | √70 × 10 |
| 80 | 89.44 | √80 × 10 |
| 90 | 94.87 | √90 × 10 |
The main purpose of the Square Root Curve is to fairly adjust students' grades in cases where an exam or assignment is particularly tough; it benefits students with lower scores by increasing their grades proportionally, making grading more balanced.
No, it benefits lower-scoring students more than higher-scoring students. The reason for this is that the square root transformation is non-linear, meaning that the students with lower scores experience a greater proportional increase.
You can use the following formula in Excel or spreadsheet to get the Square Root Curve:
=SQRT(A1)*10
Paste this formula in cell B1, where A1 contains the raw percentage grade. The adjusted curved score will appear in B1.
In a square root curve, the square root function is applied to the student's raw percentage score, which is then multiplied by 10. It benefits students with lower scores by increasing their smaller numbers significantly, while larger numbers get smaller increments, meaning lower benefits.
Let's consider this example:
Assume a student's score is 64%.
Square root curve grade = 64 x 10 = 80
The adjusted curve grade is 80%.
Yes, the square root curve is considered an optimum method when the exam is too tough or the students’ overall performance is unexpectedly low.
This method ensures that: