Garbage in, garbage out – also referred to as ‘GIGO’ is a term first popularized in the realms of computer science and mathematics. In plain language, it means that the quality of any process is determined by the quality of input.
So if there’s an incorrect mathematical equation, for example, then the answer to an underlying problem is also likely to be incorrect. In a similar vein, if you feed a computer program incorrect data, then the output is probably going to be way off the mark.
The term was originally coined by George Fueschel – an IBM programmer and computer science teacher – who used it to illustrate how a computer is only as powerful as its underlying mechanics.