Errors

The word error has different meanings in different domains. The concrete meaning of the Latin word error means "wandering" or "straying", although the metaphorical meaning "mistake, misapprehension" is actually more common. To the contrary of an illusion, an error or a mistake can be dispelled through knowledge (knowing that one is looking at a mirage and not at real water doesn't make the mirage disappear). In a similar manner, ideology can't be dispelled by simple knowledge of its existence, but only, marxists argue, by a shift in perspective.



Statistics
An error is a difference between a computed, estimated, or measured value and the true, specified, or theoretically correct value. See also errors and residuals in statistics.

Experimental science
An error is a bound on the precision and accuracy of the result of a measurement. These can be classified into two types: statistical error (see above) and systematic error. Statistical error is caused by random (and therefore inherently unpredictable) fluctuations in the measurement apparatus, whereas systematic error is caused by an unknown but nonrandom fluctuation. If the cause of the systematic error can be identified, then it can usually be eliminated. Such errors can also be referred to as uncertainties.

Engineering
An error is a difference between desired and actual performance. Engineers often seek to design systems in such a way as to mitigate or preferably avoid the effects of error, whether unintentional or not. One type of error is human error which includes cognitive bias. Human factors engineering is often applied to designs in an attempt to minimize this type of error by making systems more forgiving or error-tolerant. Errors in a system can also be latent design errors that may go unnoticed for years, until the right set of circumstances arises that cause them to become active. See also Observational error.

Medicine
See medical error for a description of error in medicine.

Aviation
See aviation safety for a description of how flying has been made safer by making the aviation system more error-tolerant.

Telecommunication
An error is a deviation from a correct value caused by a malfunction in a system or a functional unit. An example would be the occurrence of a wrong bit caused by an equipment malfunction. (Sources: Federal Standard 1037C and MIL-STD-188). See also error-correcting code and error-detecting code. A soft error is a deviation from a correct value which does not necessarily imply a malfunction.

Computer programming
An error may be a piece of incorrectly written program code. A syntax error is an ungrammatical or nonsensical statement in a program; one that cannot be parsed by the language implementation. A logic error is a mistake in the algorithm used, which causes erroneous results or undesired operation. Anti-patterns, or undesirable program design elements, may make it harder to detect or correct errors.

An error may also be an exception, a condition which arises during program execution due to an unexpected event. For instance, it is an error to attempt to write more files onto a disk that is full. Careful programmers write code that can handle errors that may occur; strategies for doing so include using error codes and using exception handling. Continuing past an unhandled error can cause error avalanche, a condition in which errors pile up and behavior becomes more erratic.

Social Context
An individual language user's deviations from standard language paradigms are sometimes referred to as errors. At present, this usage is out of favor outside of language classes. Those who recognize the role of language usage in everyday social class distinctions feel that linguistics should be descriptive rather than prescriptive to avoid reinforcing dominant class value judgments about what linguistic forms should and should not be used.

Gaffe
A gaffe is a verbal mistake made by a company or individual, usually in a social environment. The mistake comes from saying something that is true, but inappropriate. This commonly results in embarrassment or, when the gaffe has negative connotations, friction between people involved. As used by some journalists, particularly sportswriters, "gaffe" becomes an imagined synonym for any kind of mistake, e.g. a dropped ball by a player in a baseball game.

Biology
An error is said to occur when perfect fidelity is lost in the copying of information. For example, in an asexually reproducing species, an error (or mutation) has occurred for each DNA nucleotide that differs between the child and the parent. Errors in this sense are not judged as "good" or "bad", although an error may make an organism either more or less adapted to its environment.

Baseball
An error is judged by the official scorer when a runner advances a base because of a fielding mistake, and perfect play would have prevented the advancement, and the mistake was physical. Mental misjudgments are not errors. Failing to get more than one out on given play is not an error. Application of this rule is necessarily subjective. See error (baseball).