Analysis of the Behavior of People Solving Sudoku Puzzles

Grimbergen, R. and Nakamura, A. (2009).

in: The 14th Game Programming Workshop in Japan (GPW2009), pp. 79--82, Kanagawa, Japan.

Abstract

In this paper we present a method for analyzing human problem solving in the pencil puzzle Sudoku. A number of subjects were asked to solve a Sudoku puzzle and write an explanation concerning the decisions they made to solve the puzzle. From these written protocols a number of rules were extracted. These rules were then implemented in a computer program that used these rules to suggest possible squares to fill for each step in the original Sudoku puzzle. The suggestions of the computer program were compared with the decisions of the human solvers using two criteria: output ratio and cover ratio. The results suggest that human solvers prefer to fill rows and columns over subgrids unless the subgrids have very few unfilled squares.