Computer Science Lectures On GIGO

Stands for "Garbage In, Garbage Out." GIGO is a computer science acronym that implies bad input will result in bad output.

Because computers operate using strict logic, invalid input may produce unrecognizable output, or "garbage." For example, if a program asks for an integer and you enter a string, you may get an unexpected result. Similarly, if you try to open a binary file in a text editor, it may display unreadable content.

GIGO is a universal computer science concept, but it only applies to programs that process invalid data. Good programming practice dictates that functions should check for valid input before processing it. A well-written program will avoid producing garbage by not accepting it in the first place. Requiring valid input also helps programs avoid errors that can cause crashes and other erratic behavior.

TechTerms - The Tech Terms Computer Dictionary

This page contains a technical definiton of GIGO. It explains in computing terminology what GIGO means and is one of many technical terms in the TechTerms dictionary.

All definitions on the TechTerms website are written to be technically accurate but also easy to understand. If you find this GIGO definition to be helpful, you can reference it using the citation links above.

GIGO (garbage in, garbage out) is a concept common to computer science and mathematics: the quality of output is determined by the quality of the input. So, for example, if a mathematical equation is improperly stated, the answer is unlikely to be correct. Similarly, if incorrect data is input to a program, the output is unlikely to be informative.

George Fuechsel, an early IBM programmer and instructor, is generally given credit for coining the term. Fuechsel is said to have used "garbage in, garbage out" as a concise way of reminding his students that a computer just processes what it is given. The term is now widely used in computer science classes, IT services and elsewhere. In fact, GIGO is sometimes used to refer to situations in the analog world, such as a faulty decision made as a result of incomplete information.

A variation on the term, "garbage in, gospel out," refers to a tendency to put unwarranted faith in the accuracy of computer-generated data.