What's the common way to write on a academical work / essay / research / thesis / PhD that a certain professor helped me to write it? Would the word "directed" is normal in such context?
Directed by Prof. John Doe.
Or there are other or better possibilities?
Normally to any academical work there is a professor that functions as an instructor / guide / the guides or instructs the students how to do the work. I'm not sure about the correct and exact terms. But many times it's used to be in the title (except for the reference to him or giving thanks to him inside in the introduction).