Pac-Man or Pac-Bot? Exploring subjective perception of players' humanity in Ms. Pac-Man

Simulating human behaviour when playing video games has been recently proposed as an interesting challenge for the research community on Artificial Intelligence. In the exploration on Machine Learning techniques for training virtual players (i.e. computer bots) to imitate the conduct of real (human) players, we are using the classic arcade game Ms. Pac-Man as testbed. Our research goal is to find the key features that identify human playing style in this controlled environment, so we have performed an experiment with 18 human judges on how they characterise the human likeness (or absence of it) hidden behind the movements of the player’s avatar. Results suggest that, although it is relatively easy to recognize human players in this game, the factors that a judge uses to determine whether a playing style is considered human or not are multiple and very revealing for creating imitation heuristics.