Qualitative vs Quantitative Research

Quantitative research measures things with numbers and tests relationships statistically; qualitative research explores experiences, meanings and processes in words, using methods such as interviews and focus groups. They answer different questions and are often most useful together.

Comparison

When to use each

• Quantitative: prevalence, treatment effects, associations.
• Qualitative: patients' experiences, barriers to care, how an intervention works in practice.
• Mixed methods: use numbers to measure and interviews to explain.

Illustrative example

Invented for teaching. A trial finds that a medication reminder app improves adherence by 8 percentage points. Interviews with 15 users reveal that older patients found notifications confusing, which explains why adherence did not improve in that group. The combination gives a fuller understanding.

Quality in qualitative research

Qualitative research is not "less rigorous"; it uses different criteria. Reporting guidelines such as COREQ and SRQR exist; check the current versions on the EQUATOR Network site before use.

Choosing and combining methods

A practical rule is to let the question set the method: if you need to know how large or how common something is, measure it; if you need to know why it happens or how people experience it, ask them. In mixed-methods work, plan how the strands will be integrated (for example, interviews to explain survey findings) and say so in the protocol, so that the two parts answer one question rather than two separate ones.

Common pitfalls

• Judging qualitative studies by sample size alone.
• Quantifying qualitative themes as if they were statistics.

Key takeaways

• Choose based on the question.
• Both approaches can be rigorous; assess each by its own standards.

This page is general educational information about research methods. It is not medical, legal or regulatory advice; follow your institution's ethics board and your target journal's instructions.