I can see why people are surprised that drawing pictures can be considered research, particularly when universities didn't consider it to research thirty years ago. But after art schools were taken over by universities, research has become a central focus of the academy. For the last thirty years there have been countless conflicting notions of what it means to conduct research in the studio. I see two schools of thought on this issue. People like Estelle Barrett (2010) have said that while making artworks for exhibition is 'all well and good for street cred' art practice needs to serve and benefit more important disciplines like medicine or archaeology before it can really be considered research.* Others such as Graeme Sullivan (2009) maintain that the artwork itself is the product of research. For Barrett, practice as research is a means to a transdisciplinary end but Sullivan sees it as an end in itself. These two views are two ends of the practice as research spectrum, with most fine art faculty forming their own nuanced theories somewhere between.
What it means to research by making art is further complicated by the fact that there aren't many art school staff that actually have PhD's, so supervision has to be farmed out to Art Historians (in my case) or other fields that relate to the candidate's focus. In any case research in art practice is young with few elders to lead the way. But the foundations grow with every new researcher that emerges.
But that's just the institutional stuff. If you really want to look at great research done by artists, all you need to do is look at great artists' works to see what they're doing. David Hockney is a textbook example of an artist whose work easily fits anyone's understanding of research. When you look at Hockney's work from 1960 to now you see his constant mission to develop better strategies for depicting space. He investigates (plays with) new technologies and compositional techniques borrowed from maps and Chinese scrolls. His paintings pass knowledge down to new generations of picture makers about how to make more engaging images of the world around us - and thus, how to think about our place within that world. Part of the reason Hockney is such a clear example of research-by-doing is because he freely shares the how and the why of his work in countless interviews and documentary films. But if he hadn't interpreted it for us, his knowledge would still exist in the paintings, drawings, and prints that he's produced over his life-time.
On the other hand, Lucian Freud participated in very few interviews in his lifetime. His legacy is almost entirely in the paint. You can see from the 1940s to the 1960s how he progressively developed a way of painting thick brushstrokes loaded with several pigments to convey really dense pictorial information about the human body. He began to suggest rather than describe the figure's anatomy underneath their skin - the musculature and skeleton, all in their un-idealized unique form. He must have learnt how to handle paint from Rembrandt who lived centuries ago, and he then used Rembrandt's lessons to show us real bodies. To do this he had to discover a way of working with his subjects - making them comfortable, choosing models who would pose for long periods of time so that he could paint from life. These paintings document his research and they are his results.
These two examples are not the quintessential examples of research undertaken by artists, but they're examples that shape my own research into how best, in today's age of post-photographic, relativistic and technologically inter-connected world, how the human self can best be represented. In other words, how can artist's make portraits that address concerns of humanity and contemporary aesthetics? To do this I've had to interrogate (play with) the laws of images, particularly abstraction and modes of realism, I've also had to read about issues in the philosophy of self, in aesthetics, and in the contemporary art world. Most of all I've had to make lots of artworks, critiquing them, judging them on the basis of the theory and practice that I've learned so far.
When people ask me about the art PhD, I'm pretty lucky if I ever get this far into the answer. Incidental distractions plus my inability to articulately and succinctly explain issues of practice as research, off the cuff and after a few beers, means that I never really feel like I've gotten my point across. But then again, who am I trying to fool?
* I'm paraphrasing Estelle Barrett here from a practice-as-research workshop she gave at Charles Sturt University, Wagga Wagga in 2012. Barrett was discussing the role of writing as essential to the getting practice counted as research within university bureaucracy. She used the term "street-cred" to explain that while the making and exhibition of work had value to an artist's reputation to an artist, it did not have value in terms of research. I fundamentally disagree with her position and see it as dangerously patronizing to any and all art practice. I equate it to saying that laboratory experiments are not important for scientific research and that report writing is the key to to scientific discovery.