GIGO

Garbage In, Garbage Out (abbreviated to GIGO, coined as a pun on the phrase First-In, First-Out) is a phrase in the field of computer science or information and communication technology. It is used primarily to call attention to the fact that computers will unquestioningly process the most nonsensical of input data (garbage in) and produce nonsensical output (garbage out). It was most popular in the early days of computing, but applies even more today, when powerful computers can spew out mountains of erroneous information in a short time. It is also commonly used to describe failures in human decision making due to faulty, incomplete, or imprecise data.