Method follows the question
A common mistake is to choose a method before getting clear on the question. The better order is the reverse. Let the research question tell you which method fits.
Quantitative research
Quantitative research deals with numbers. It suits questions about measuring, comparing, or testing relationships across a sample large enough to generalise. If your question asks how many, how often, to what extent, or what the relationship is between two things, you are probably in quantitative territory.
Its strengths are objectivity, the ability to test hypotheses statistically, and results you can generalise. It relies on structured instruments such as questionnaires, and on tools like SPSS or STATA for analysis.
Qualitative research
Qualitative research deals with meaning. It suits questions about experiences, perceptions, or processes that you want to understand in depth. If your question asks why, how, or what something means to people, qualitative methods fit.
It uses interviews, focus groups, and observation, and tools like NVivo for coding. The strength is depth and context. The trade-off is that the findings are not statistically generalisable.
Mixed methods
Mixed methods combine the two. You might survey a large sample to find patterns, then interview a smaller group to explain why those patterns exist. The approach is powerful, but it asks more of you. You need competence in both traditions and a clear reason for how the two strands fit together.
How to choose
Ask yourself three things. What does the question actually require, measurement or meaning or both? What time and resources do you have, since mixed methods are heavier? And what is normal in your field, since some disciplines lean strongly one way.
Neither approach is superior. A well-run qualitative study can be more valuable than a poorly designed survey, and the reverse is true too. Rigour decides quality, not the method.
For most masters dissertations in the social sciences, a well-designed quantitative or qualitative study is plenty. Save mixed methods for when the question genuinely cannot be answered any other way, and when you have the time to do both strands justice.