Because the adjectives qualitative and quantitative are antonyms, they’re often used in contrast with each other, and their close association and similarity in sound makes them easily confused. The distinction is simple: quantitative relates to numbers and amounts, while qualitative relates to nonnumeric characteristics and properties.
Both qualitative and quantitative are preferred over their shorter alternatives, qualitive and quantitive.
Examples
Quantitative
And this week, after a paper in the Lancet, for the first time we have quantitative data showing how patients are harmed by these delays. [Guardian]
Yet quantitative promises about cuts in emissions have become the be-all and end-all of international negotiations. [The Economist]
There is no quantitative measure, no body count that must be met before airstrikes begin. [National Post]
Qualitative
It makes a qualitative change in the movie-going experience, no doubt. [NPR]
It was only during the past decade and a half that the situation underwent a qualitative change. [Telegraph]
The women’s march, though only part of the rising anger against the military, marked a qualitative shift in the way the broader public perceives Egypt’s military leadership. [Wall Street Journal]