How different are qualitative and quantitative research?

Quantitative and qualitative research are often spoken of and written about as though they are completely different. They have even been set up in opposition to each other, in the so-called ‘paradigm wars’. Yet this adversarial binary formulation is at best inaccurate, at worst damaging to research. To mark the publication of her new book Qualitative Research for Quantitative Researchers, Dr Helen Kara (Independent Researcher) introduces the two and discusses their differences – and their similarities. 

Both quantitative and qualitative research have strengths and limitations. In very simple terms, quantitative research is usually good at identifying what is happening, while qualitative research is usually good at identifying why or how that is happening. 

Quantitative research can tell us which brands of jam people like best by using sales figures as data. If that is all you need to know, then quantitative research is enough. But if you want to know why a top brand sells so well, qualitative research can help you to answer questions such as: is the flavour of the jam the most important factor? Or its texture? Or the price, or the packaging, or how well it spreads on bread? Are there other relevant factors such as shopper’s preference? And so on. Another way to describe this could be to say that quantitative research counts and measures things, while qualitative research provides deeper insight into intangible factors such as emotion and experience.

There is currently a general encouragement for researchers of all kinds to know more about methods, so that they have more tools in their research toolbox. Among other things, this is leading quantitative researchers to learn more about qualitative methods, and vice versa. And it is not entirely a new phenomenon. Conventionally quantitative disciplines have been branching out into qualitative research for some decades now. This is due to people’s realisations that (a) quantitative information often provides only partial knowledge, and (b) including qualitative information can provide a fuller and richer analysis. Among others, economists were in the vanguard, embracing qualitative methods in the 1960s; physicists and psychologists followed suit in the 1980s, and engineers in the 2010s. 

There are a couple of unhelpful myths about quantitative and qualitative research: that quantitative research always requires numerical data, and that qualitative research involves everything but the numbers. In fact, the data for quantitative research may not be numerical: it may be human or animal tissue, collected or cultivated bacteria, people’s self-reported emotions or impulses. It may be any non-numerical phenomena, so long as those phenomena can be counted or measured, and so converted into numbers for analysis. And qualitative research, too, often takes note of numbers: how many participants, what proportion of interviewees said X or Y, how long it took to collect the data.

Of course there are some differences between quantitative and qualitative research. First, they are based on different kinds of reasoning. Quantitative research is based on deductive reasoning. The researcher formulates a hypothesis and then conducts experiments to test that hypothesis and so reach (or deduce) a conclusion. Qualitative research is based on inductive reasoning. The researcher works in a more exploratory way, drawing on a range of inputs and being open to revising their approach if circumstances suggest they should. Again this is not a hard-and-fast distinction, as qualitative researchers also use deductive reasoning at times, and quantitative researchers may also use inductive reasoning. But the emphasis is on deductive reasoning in quantitative research, and inductive reasoning in qualitative research.

Another difference is in the ways quantitative and qualitative researchers think about the research context. Quantitative researchers try to minimise the impact of the research context so that they can isolate and manipulate variables. Qualitative researchers see the research context as a relevant factor and a potential resource. And a third difference is in how they think about research quality. Quantitative researchers value concepts such as representativeness and generalisability, whereas qualitative researchers value concepts such as relevance and credibility. 

So there is a distinction to be made between quantitative and qualitative research. Their differences are real and often very useful. But it is misleading to treat them as though they are completely separate. There are considerable overlaps between them, and at times the distinction can break down completely. Quantitative and qualitative research are not oppositional but can play complementary parts in helping us to understand and overcome real-world problems.

Binary thinking is generally to be avoided because it inclines people towards polarisation, competition, and conflict. We will all be better researchers if we can break away from binary thinking. Fortunately the ‘paradigm wars’ are one conflict where the 21st century seems to be bringing peace and reconciliation. As part of that process, we are beginning to understand that some research methods may be common to quantitative and qualitative research. This applies particularly to methods of reporting research results and presenting and disseminating research findings. And writing – the research method that hides in plain sight – is used by all Euro-Western researchers. Even the most quantitative research cannot be reported entirely through pages of calculations and equations, graphs and charts. An accompanying narrative is essential to explain the importance of trends, highlight outliers, and generally tell the stories in the data. And writing is a qualitative method.

Of course there is much more to say about all of this; I can only fit a brief introduction into a blog post. If you would like to find out more, you can read Qualitative Research for Quantitative Researchers or attend the course I am running on the subject for the Methods@Manchester 2022 Summer School.

Bio: Helen Kara has been an independent researcher since 1999 and an independent scholar since 2011. She writes books on research methods, research ethics, and academic writing. Helen is the author of Qualitative Research for Quantitative Researchers (SAGE, 2022) and is running a course on the subject for the Methods@Manchester 2022 Summer School.