As illustrated by those examples, random walks have applications to engineering and many scientific fields including ecology, psychology, computer science, physics, chemistry, biology, economics, and sociology. Random walks explain the observed behaviors of many processes in these fields, and thus serve as a fundamental model for the recorded stochastic activity. As a more mathematical application, the value of can be approximated by the use of a random walk in an agent-based modeling environment. The term "random walk" was first introduced by Karl Pearson in 1905.