Thousands of people arrive at this blog wanting to know what is the difference between qualitative and quantitative research. Qualitative versus quantitative research is by far the most popular post on this blog. In that first post, I explained why sample size doesn’t matter in qualitative research. In this post, I explain why qualitative research is generally a better approach for design research.
Notice how the qualitative process is iterative with the going back and forth from data to sense-making or developing theory. It is flexible and can change direction easily.
Qualitative design process
And the quantitative design process is very linear, and does not include an iterative component:
If your design process involves an iterative prototyping phase, for example, then qualitative research is likely the best approach for you. Notice also that qualitative research necessarily involves the researcher putting herself in the shoes of the user. Quantitative research does NOT require the researcher to see through the eyes of the user.
Designers often want to empathize with their users. They want to understand their experiences and pain points. They want to know what their users are thinking. This is why qualitative research is often better suited to design research.
See also this embedded slideshow from my research design class. This should give you the basic differences between the two.



6 responses so far ↓
Harry // October 9, 2008 at 7:15 am |
Hi Sam, nice post. As a user-centred design practicioner, there’s a couple of things I’d add to your great summary.
Firstly, qual and quant are usually brought in at different stages of the design process. When you have no product to test yet, or when you only have a sheet of vague requirement specs, qual is the only way to go. Later on, once the product has taken shape, you move into the business of nailing down the finer details and optimising your design decisions. These two different stages are often refered to formative (early on) and summative (later on) evaluation.
Today, with web-based products & services, quantiative research is very popular for live products because once they are out there, it’s trivial to collect behavioural data and to compare the effects of design changes using before/after, A/B or multivariate testing. In this context, quantitative research is much cheaper than qualtiative research – there’s no recruitment cost and it’s easy to get high volumes of users. Conversely, with face to face research, quantitative is a lot more expensive.
sladner // October 9, 2008 at 12:04 pm |
Very true, Harry.
I particularly agree about when to do qual and quant research (see my other post regarding that).
Stein Communications The Scoop » Blog Archive » A Research Resource // October 16, 2008 at 11:47 am |
[...] qualitative and quantitative research on her blog, Design Research, and has added a nice, succinct post that gets at the fundamental benefits of qualitative research, viz. that it’s [...]
Quantitative vs. Qualitative Research | Michael Roller // October 24, 2008 at 2:04 am |
[...] techniques, but Sam Ladner has given great definitions to these two types of design research on his blog. The qualitative process is iterative with the going back and forth from data to sense-making or [...]
Imtiaz Manzar // October 30, 2008 at 7:40 am |
Would appreciate more compartive studies regarding Qual versus Quant
OKUMU-RINGA PATRICK ALOY // March 19, 2009 at 9:34 pm |
I have read this article and have made good use of it in my discussion with course=mates in my PhD Public Policy class year 3.
Can you give more articles on the various aspects of research designs.
Okumu-Ringa P.A. /okumuringa@yahoo.com