Garbage In, Garbage Out

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. The term was coined as a teaching mantra by George Fuechsel,^[1] an IBM 305 RAMAC technician/instructor in New York. Early programmers were required to test virtually each program step and cautioned not to expect that the resulting program would "do the right thing" when given imperfect input. The underlying principle was noted by the inventor of the first programmable computing device design:

On two occasions I have been asked,—"Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?" ... I am not able rightly to apprehend the kind of confusion of ideas that could provoke such a question.

—Charles Babbage, Passages from the Life of a Philosopher^[2]

It is also commonly used to describe failures in human decision making due to faulty, incomplete, or imprecise data.

The term can also be used as an explanation for the poor quality of a digitized audio or video file. Although digitizing can be the first step in cleaning up a signal, it does not, by itself, improve the quality. Defects in the original analog signal will be faithfully recorded, but may be identified and removed by a subsequent step. (See Digital signal processing.)

Garbage In, Gospel Out is a more recent expansion of the acronym. It is a sardonic comment on the tendency to put excessive trust in "computerized" data, and on the propensity for individuals to blindly accept what the computer says. Because the data goes through the computer, people tend to believe it.

Decision-makers increasingly face computer-generated information and analyses that could be collected and analyzed in no other way. Precisely for that reason, going behind that output is out of the question, even if one has good cause to be suspicious. In short, the computer analysis becomes the gospel.^[3]

See also

• FINO

References

This article was originally based on material from the Free On-line Dictionary of Computing, which is licensed under the GFDL.

1. ^ Butler, Jill; Lidwell, William; Holden, Kritina (2010). Universal Principles of Design (2nd ed.). Gloucester, MA: Rockport Publishers. p. 112. ISBN 1-59253-587-9. http://books.google.com/books?id=l0QPECGQySYC&pg=PA112#v=onepage&q&f=false. Retrieved 2011-04-26. 
2. ^ Babbage, Charles (1864). Passages from the Life of a Philosopher. Longman and Co.. p. 67. OCLC 258982. 
3. ^ Daniel T. Brooks, Brandon Becker and Jerry R. Marlatt, "Computer Applications in Particular Industries: Securities" appearing in Bigelow, "Computers & The Law", American Bar Association, Section of Science and Technology, Third Edition 1981 at 250, 253.