Grading on a Curve Is a Statistical Idea
A curve is a line that bends. In education, grading on a curve means fitting marks to a distribution rather than a fixed scale.
A curve is a smoothly bending line, or the act of bending. *Grading on a curve* means something specific: instead of awarding marks against fixed thresholds, the teacher fits results to a distribution, so a student's grade depends on how everyone else did. The curve in question is the bell curve of the normal distribution. The Latin root *curvus*, bent, also gives *curb* and *curvature*.
- A bending line. *A gentle curve.*
- To bend. *The road curves left.*
- A graph line. *The demand curve.*
- Grade on a curve — fit marks to a distribution. *Graded on a curve.*
- Curveball — an unexpected difficulty. *Thrown a curveball.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | curve | A sharp curve. |
| Plural | curves | Two curves. |
| Verb | curve | It curves. |
| Adjective | curved | A curved wall. |
| Noun | curvature | Spinal curvature. |
- The road curves sharply here.Physical.
- The learning curve was steep.Figurative.
- The class was graded on a curve.Education.
Famous curves by name
- Bell curve — the normal distribution
- Learning curve — skill plotted against practice
- Demand curve — quantity plotted against price
- Curveball — a baseball pitch that breaks sideways
- Ahead of the curve — earlier than the general trend
Latin *curvus*, bent or crooked, through the verb *curvare*, to bend. English used it as a verb from the 1400s and as a noun from the 1600s.
What does a steep learning curve mean?
In common use, that something is hard to learn, though a mathematician would read a steep curve as fast progress.
What is grading on a curve?
Assigning marks by ranking students against each other and fitting the results to a distribution, rather than to fixed thresholds.