What is the correct usage?
a) I am working as the consultant for two projects in (on) sustainable development.
b) I am writing a research paper on (in) women's health.
c) I am doing research in (on) robotics.
Hello Shon, welcome to UE!
In these examples, "in" suggests "in the field of", whereas "on" suggests "on the subject of".
So you might say that "in" suggests a "from the inside" approach, while "on" suggests a "from the outside" approach.
I would probably use "on" for the first two; for 3, you also have the option "research into", which might be best.
All the best,