anywhere

I have recently been invited to Georgia Tech by the mechanical engineering department to tour and talk to some professors about assisting in research. I know this is a good sign, but I am curious about my chances for acceptance at this point. Does this mean I am close to admission? Or do I still have a ways to go? And I was also wondering how many steps there are when trying to get a GRA/GTA position. Would this only be the first round of interviews, or is this the only round? Any info would be greatly appreciated!