If you hate the color and print and style of your sister's shirt, you are making a qualitative judgment. If you hate how many shirts she has, that would be quantitative.
Qualitative is one of those words used often in scientific writing because it makes an important distinction among characteristics. When you're making any sort of judgment or distinction, it's key to know whether it's based on the actual qualities of the thing at hand — its color, shape, temperature, etc — or on how many there are (quantitative), your own personal bias (personal), or just how you feel in the moment (random).
