The various processes of both qualitative and quantitative research are what can be used to differentiate between the two. Qualitative research does not really focus mainly on data gathering but pays utmost priority on the various proceses that will help during data collection and development. Quantitative research focuses more on data collection that involves a large number of people or candidates.
In contrast, qualitative research does not really aim at gathering big data. In fact, qualitative research is most effective for smaller groups, whereas you can consider quantitative research for larger groups. Qualitative research usually adopts the use of questionnaires, interviews, and also encourages the full participation of all the subjects being used.
That is why more time is needed when selecting subjects for qualitative research. Quantitative research only requires more time during data processing and does not really give much priority to subject selection. Qualitative research also requires the use of more research techniques.