Personally, I think written agreement is definitely better, because the verbal agreement needs proof of people being there or a video recordings. These proofs can be changed with the current technologies or you can bribe a person to change the statement. The written agreement, is the best way to go because you have everything listed from what you are working on to how much you will be paid. People usually don’t break this kind of agreement as it might be hard for them to win in the court so its basically pointless. In addition, as dr. simon mentioned the written agreements are more preffered in the companies and are also more used in generally. However, if you want to start working on a project, you can do it while being on verbal agreement, but I would personally get written agreement down the line.