Resignation methodology Is there a method to determine whether or not a player should continue playing, or resign?

I would currently consider myself a beginner at chess. So when for example I make a bad decision and lose a lot of material early, I will be naturally deflated from the loss and be tempted to resign.
It depends on your level. At the beginner level, most people recommend not resigning and instead playing until there is either checkmate or a stalemate. If you're a beginner playing against other beginners, blunders are so common that even being a queen behind doesn't guarantee losing.

Once you get past the beginner level, an easy way is to ask yourself if you know how you would force a win if you had the other side's pieces. If you do, then you would consider resigning.