Once participants are chosen, researchers must decide how to measure what they're studying — with numbers or with descriptions.
Interviews and open-ended survey questions often collect qualitative data because participants answer in their own words.
A Likert scale measures feelings, opinions, and attitudes with numbered responses, so it collects quantitative data.
Qualitative and quantitative describe types of data, not research methods; experiments, correlational studies, case studies, and naturalistic observations can collect either or both.
Key terms
quantitative data
Data collected as numbers, such as rating stress from 1 to 10.
qualitative data
Data collected as descriptions, with participants answering in their own words.
Likert scale
A measure of feelings, opinions, or attitudes where participants choose one of several numbered responses.
Watch out
Qualitative and quantitative are not research methods — they describe the type of data, and one method (like naturalistic observation) can collect both.