Coefficient
Etymology
From Latin co- (together) plus efficiens (effecting), from efficere (to bring about), so a coefficient “works together” with a variable. The term was established in 16th- and 17th-century algebra.
noun · /koh-uh-FISH-uhnt/
A number that multiplies or scales a variable, setting how strongly it matters in a formula.
What it names
It is the dial that tunes a relationship — the size of the coefficient is often the whole finding.
Example
In a formula where cost equals 5 times distance, the coefficient 5 is what tells you each extra mile adds five dollars.
Related idea
A correlation coefficient is one special, standardized kind of coefficient; in a regression, each coefficient estimates how much its variable moves the outcome, which is where the substantive claim lives.