This is interesting because it seems so straightforward and obvious, but really thinking about it led me to a series of conclusions that really show both the similarities and differences between academia and industry.
Here's the "obvious" answer (well, obvious to anyone in industry): you don't. Industry largely ignores academic research. This isn't because game designers are a bunch of haters, it's for purely pragmatic reasons:
- Academic papers tend to be "rigorous" which is a nice way of saying that they take forever to read before you get to the useful parts;
- Even if we did have time, there's a dearth of peer-reviewed academic journals that specifically address game design, so we would have to hunt through all kinds of unrelated journals just to find something that's even relevant to the field;
- A lot of academics have no understanding or experience of industry, and therefore publish research that is useless to practitioners, so you have to read through multiple game design papers just to get one that you can use at all.
But wait -- does that mean that the field of game design is stagnating, if there is no way to push cutting-edge research to the field? Quite the contrary; we see innovative and iterative designs all the time. So how does the field build on itself, if there's no research? Thinking about this uncovers a flaw in the original question: it is built on some assumptions about the function and form of academic research.
In the sciences, at least, here's how it works. Suppose you're a research faculty. You do some research. You publish your results in a peer-reviewed refereed journal. Professional R&D folks in industry follow at least the top-tier journals to stay current on cutting-edge techniques and technology. The academic journal represents a primary source of knowledge that builds on itself over time. The original question assumes that game design works like this too. It doesn't.
Here is how professional game designers do research: they play games. Unlike other parts of a video game, the design is laid bare whenever you play. By playing you can explore the mechanics that were designed. Any mechanics that are hidden from you, such as combat formulas or enemy stats, can be found in a published hint guide (which is the closest thing we have to a public design document, most of the time). This allows us to analyze and study games directly. We ask questions like "how do these mechanics create a positive or negative player experience?" and "why did the designer choose to implement that feature in this particular way?" and "what are the weak points of this game, and how would we fix it?"
It is really a wonderful form of "publication"; imagine if scientists did not merely publish the results of their experiments, but also made their petri dishes and cell lines and laboratory equipment and whatnot available, and these were included in each journal so that the reader could precisely replicate their experiments at home! This is what published games are for game designers. Play is the game design equivalent of reading an academic journal. (Oh, how I love this field.)
So, this brings us to the non-obvious answer to the original question: to contribute to the field of knowledge that is game design, make a game and release it. If your game does something interesting, game designers will play it, analyze it, pick it apart, learn from it, and incorporate its lessons into their future designs.
It also means that all game designers, whether in academia or industry, are doing cutting-edge research, and every published game is peer-reviewed.