Cargo cult science is a pseudoscientific method of research that favors evidence that confirms an assumed hypothesis. In contrast with the scientific method, there is no vigorous effort to disprove or delimit the hypothesis. The term cargo cult science was first used by physicist Richard Feynman during his 1974 commencement address at the California Institute of Technology. Cargo cults are religious practices that have appeared in many traditional tribal societies in the wake of interaction with technologically advanced cultures. They focus on obtaining the material wealth (the "cargo") of the advanced culture by imitating the actions they believe cause the appearance of cargo: by building landing strips, mock aircraft, mock radios, and the like. Similarly, although cargo cult sciences employ the trappings of the scientific method, they fail—like an airplane with no motor—to deliver anything of value. Feynman adapted the speech into the final chapter of his book Surely You're Joking, Mr. Feynman!. He based the phrase on a concept in anthropology, the cargo cult, which describes how some pre-industrialized cultures interpreted technologically sophisticated visitors as religious or supernatural figures who brought boons of cargo. Later, in an effort to call for a second visit the natives would develop and engage in complex religious rituals, mirroring the previously observed behavior of the visitors manipulating their machines but without understanding the true nature of those tasks. Just as cargo cultists create mock airports that fail to produce airplanes, cargo cult scientists conduct flawed research that superficially resembles the scientific method, but which fails to produce scientifically useful results. The following is an excerpt from a speech (taken from the book): In the South Seas there is a cargo cult of people. During the war they saw airplanes land with lots of good materials, and they want the same thing to happen now.