Qualitative data is data that can be observed but cannot be measured. This type of data is often in contrast to quantitative data, which is data that can be measured.
Qualitative data stems from the word quality and characterizes attributes or properties of an object. When comparing qualitative and quantitative data, a key difference is that quantitative data is measured in numbers. For example, qualitative data for a painting includes a description of the characteristics of the painting such as colors and the way it is painted. Quantitative data for the same painting includes measured data like its cost, which can be measured in dollars.