Interleaving Fast and Slow Decision Making
  The "Thinking, Fast and Slow" paradigm of Kahneman proposes that we use two
different styles of thinking -- a fast and intuitive System 1 for certain
tasks, along with a slower but more analytical System 2 for others. While the
idea of using this two-system style of thinking is gaining popularity in AI and
robotics, our work considers how to interleave the two styles of
decision-making, i.e., how System 1 and System 2 should be used together. For
this, we propose a novel and general framework which includes a new System 0 to
oversee Systems 1 and 2. At every point when a decision needs to be made,
System 0 evaluates the situation and quickly hands over the decision-making
process to either System 1 or System 2. We evaluate such a framework on a
modified version of the classic Pac-Man game, with an already-trained RL
algorithm for System 1, a Monte-Carlo tree search for System 2, and several
different possible strategies for System 0. As expected, arbitrary switches
between Systems 1 and 2 do not work, but certain strategies do well. With
System 0, an agent is able to perform better than one that uses only System 1
or System 2.
