Chapter 1: Pokerface

At the start of my internship I needed to get used to the environment and meet all kinds of different people who I might be working with. It quickly became clear that I needed to figure out what kind of project I wanted to do here; they gave me freedom to do whatever I wanted, as long as it fit in with recent ICT studies.

As stated in the introduction, one of their studies looked at the influence of a virtual human’s facial expressions on a human player while playing a game called Iterated Prisoner’s Dilemma. However, the avatar only showed a brief facial expression after a round was done; it was not possible to infer the computer’s decision based on his face. If two human players were playing this game, one of the players might be able to guess what decision the other player has made based on an (involuntary) expression.

Source: C. De Melo, L. Zheng and J. Gratch, "Expression of Moral Emotions in Cooperating Agents," in 9th International Conference on Intelligent Virtual Agents, Amsterdam, 2009. 

I decided to focus more on that part of facial expressions in games. However, the Iterated Prisoner’s Dilemma is not an ideal scenario to look for facial expressions, because a player’s goal is not very clear. If a player shows a genuine smile, the meaning of this smile is still ambiguous; he/she might smile out of either competition or cooperation. In order to remove this ambiguity I needed to design a new game where a player’s goal is always obvious. Since we will be looking at facial expressions during gameplay, I started thinking of bluffing in a poker game, so why not let people play a game of poker against each other?

Unfortunately there are a couple of good answers to this simple question. We would need to take a player’s existing poker playing experience into account, especially when an experienced player is matched against an inexperienced player. There are a lot of different variations of poker, and even though Texas Hold’Em is considered to be the most popular by far, it is also the most complex to analyze; we want to be able to tell what a person is thinking when he/she makes a decision.

To remedy or reduce all of these problems I designed a new game that is a drastically simplified version of poker. Players receive a single card between 2 and 10 and they only have 4 different betting options: No bet, low bet, medium bet or high bet. Additionally, the players will have a limited time to make their betting decision, but this betting decision will only be revealed to the other player when this time has passed. This is done to reduce an experienced player’s ability to ‘intimidate’ a less experienced player by placing bets instantly. The players will play for a limited amount of rounds and will start out with enough chips to place high bets every round if needed. We will record all facial expressions during the game and analyze these to possibly find differences between bluffs, tells and general smiles. This information can then be used for a more realistic virtual human playing a similar pure-competitive game. A quick and dirty preview:

This preview has a working server back-end (meteorJS) that sends and receives messages from the Javascript front-end. The card is made completely in CSS with fancy transforms that allow you to rotate the card to put it face down.