Product Management: Foundations to Practice · Customer Discovery and Research
Qualitative vs Quantitative Research
Qualitative and quantitative research answer different questions and neither substitutes for the other. This chapter covers when to use each and the specific failure modes of relying on only one.
Qualitative research, such as customer interviews and usability sessions, reveals why people behave a certain way and surfaces problems a team did not know to look for, but it cannot tell you how many people share that problem, since sample sizes are typically small and non-random. Quantitative research, such as analytics data and surveys at scale, tells you how widespread a pattern is across a large population, but rarely explains the underlying motivation behind the numbers on its own.
- Qualitative research explains why; quantitative research shows how widespread a pattern is.
- Effective discovery typically sequences qualitative hypothesis generation with quantitative validation, or vice versa.
- Quant without qual risks misreading what a metric actually means for the customer.
- Qual without quant risks over-indexing on a single vocal customer who may not represent the broader base.