What is Garbage in Garbage out?

Mary McMahon
Mary McMahon

Garbage In Garbage Out (GIGO) is popular computing slang for “if you input the wrong data, the results will also be wrong.” The term arose in the programming community, where instructors remind students that they must check and re-check their data and coding to ensure that the results are valid. The term is also widely used in other industries, most notably in the recording industry, where people stress the need for good equipment. In this case, a poor initial recording will result in an album of low quality.

The expression "Garbage In Garbage Out" originated in the programming community.
The expression "Garbage In Garbage Out" originated in the programming community.

George Fuechsel, an early IBM programmer, is generally credited with coining the term. He reminded students that computers will process any kind of information they are given without judgment or an eye for accuracy. If mistake is made in the program, however small, it can result in Garbage In Garbage Out, and thereby create an unintended result. As long as people are aware of the fallibility of computers, this concept isn't a big issue, although it can be frustrating on a major project. It does, however, become a problem when people accept information on faith simply because it came from a computer.

When this happens, it is sometimes jokingly called Garbage In Gospel Out. Many computer users are guilty of assuming that computers are infallible and will always return correct results. This can cause serious problems. On a minor level, someone could simply have incorrect facts about a situation; on a major level, someone could base a serious decision on erroneous information.

Programmers try to be aware of the GIGO principle, and in fact many computers have the capacity to check code for basic errors. Most input data, however, still needs to be proofread, especially if it is complex and filled with multiple arguments, which usually is the case with advanced computing. This is one reason scientists like to confirm data with other scientists — to ensure that their calculations are correct.

The principle of Garbage In Garbage Out can apply to many things in life. Cooking with poor quality ingredients, often results in a disappointing meal. Likewise and on a more serious level, students who suffer from a poor education often struggle to succeed in life. The lesson is to ensure that something is of good quality before you use it, whether it's code or a new central heating system.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a EasyTechJunkie researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

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Discussion Comments


"@Subway" - I agree for the most part with the assumption that if a child is given a subpar education than it will create the same type of result from the child.

However, I had a friend who went to a public high school that was not very regarded, but despite the poor teachers, my friend signed up for the hardest classes and studied really hard.

It paid off because she got accepted to NYU and later became a lawyer. While cases like this come from very motivated students, there are people that can rise to the occasion regardless of the poor circumstances they are dealt.

But I have to say that I do think that it is sad that a country like the United States is ranked 25th internationally in math. The garbage in and garbage out principle does apply and we should look at ways to change the education system and maybe offer more charter schools so that kids can have a choice when it comes to their education and not be destined to repeat the same generational failures of the past.

The movie, "Waiting for Superman" really discusses this option at length.


I think that the garbage in and garbage out can really relate to the educational system of the United States.

If a child goes to an elite private school they will probably produce higher quality work that may provide scholarships based on their academic record. This student is also likely to flourish in college because they are well prepared for college.

By contrast a child that grows up in a public school system will not receive the same caliber of education and therefore will not produce the same academic results that the child that went to better private school did.

The results of children that attended public school are really dismal. In fact about 32% of eight grade students in public school can read at grade level and only 12% of students in Washington D.C. that attend public school can read at grade level once they reach eighth grade.

Many of the public high schools also have a 50% graduation rate while most private high schools boost graduation rates in the ninety plus percentile.

In addition, most graduates from a private high schools attend some form of post secondary education whether it be college or a vocational school. The quality of the child’s education does have a tendency to determine the outcome of a child’s future academic success.

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