Quantitative and qualitative paradigms are two research approaches that look at the world through different lenses. The quantitative approach is interested in objectivity and generalization of results, while qualitative approach wants to understand the experience of a phenomena and dig deep, not concerning itself (as much) with making generalizations and predictions.
A stereotypical quantitative researcher sees the world as a lab. They tend to have functionalist views. He or she stays on the outside — separated from the object of the research — measuring, calculating and performing statistical analysis to establish causal relationships between different variables and parameters and/or testing hypotheses. Their reality is seen as constant and predictable, and if their study is repeated, one should get the same results and reach the same conclusions.
A good qualitative researcher, on the other hand, becomes one of the tools of the research (some refer to this as “self as instrument”). He or she immerses themselves in the phenomenon under study to be able to understand it better. He or she listens, asks, observes and gathers the material and data that is then analyzed using different qualitative methods. In the qualitative world, there is a notion of “multiple realities” that are always changing and undergoing transitions. It is the context of the subject being studied that matters, and findings can only be tentatively generalized to situations with similar context and circumstances.
In short, if quantitative research is about numbers and repeatable results, qualitative research is about words, descriptions and refined meanings.
How do you know which approach to use?
In the past, qualitative research was often marginalized by those in academic fields and viewed as inferior. It took qualitative researchers a long time to legitimize their research methods as valid and important as their colleagues’ from the quantitative camp. Also, in some fields and areas of research, a qualitative approach is still a rarity, while in others, such as psychology and social sciences, it is becoming more established and well-respected.
You should not choose a quantitative research method just because it provides you with generalizable results or is more common in your field of practice. Generally speaking, quantitative and qualitative methodologies have their strengths and weaknesses, so your approach should be dictated by your research question.
Although it may require more work you might consider a mixed-methods approach. The two approaches are compatible and can complement each other well. A qualitative approach might be used in the first stage of a study when little is known about the subject. Later on, when quantitative methods are added, the preceding qualitative findings can help interpret the quantitative data. Or, the opposite might be required: a study can start with a quantitative survey/analysis, followed by a qualitative part that helps to go deeper and extract meaning from whatever is being examined.
Before you get started you need to ask yourself:
- Are you interested in causal relationships and want to explore correlations between different variables?
Or
- Are you interested in people’s subjective experiences and the meaning they attribute to what happens in their daily lives?
For example, if you want to study the effect a certain drug has on blood pressure, you probably want to use quantitative methods (ex. measure blood pressure pre- and post drug administration and compare the results). However, in contrast, if you want to understand how people with high blood pressure go about their daily lives and what adaptations they need to make, you may want to conduct interviews and observations thus employing a qualitative approach.
Again, the most important element to consider is to make sure that your research question clearly reflects the methodology that is going to be used, and vice versa.